CASE STUDY

- An example of a company that may embark on computerisation due to the above reasons may be a company called Jack & Sons Suppliers (JSS) that supplies electronic gadgets throughout the country.

- This company has the following departments:

i) Sales department which accepts and process clients’ orders.ii) Credit control department which deals with client credit

details.iii) Stores department which handles goods storage and stock

control.iv) Invoicing department.v) The accounts department which handles general accounts.vi) Purchasing department which places orders of goods with

suppliers.vii) Sales and Marketing department responsible for

advertisements and establishing new clients.viii) Payroll department.ix) Maintenance department for general maintenance including

company vehicles.x) Administration department.

The customer base for the company has decreased and the processing of orders has slowed down and again a new company with better communication facilities has been established throughout the country i.e. the market has been invaded and therefore there is need to fight off this competition. One of the possible solutions is computerisation. Computerisation will also further broaden JSS’s customer base.

JSS hires a systems analyst to discuss the current problem and opportunities. The analyst’s task is not immediately clear to him, and neither is it to the steering committee of the project nor the management.

The best approach is to let the analyst come up with a written statement of the scope and objectives of the project (Project Proposal). He gets a rough idea of the problems/opportunities that may be realised from the project initiators (the steering committee and users). He then studies the problem and environment of the existing system after which he will produce the written statement on the problems that should be addressed, as he perceives them.

This statement of scope and objectives of the project will also provide rough estimates of costs to be incurred and this information is going to be the basis of his feasibility report. The analyst realises the problem area to focus on as a start is the Sales orders processing department that covers customers orders processing (front and back office), invoicing (accounts) and the stock processing areas ( warehouse).

This initial investigation may take a day or two. The statement of scope and objectives document should be structured as follows:

THE HEADING:

Statement of scope and objective (project proposal)

PROJECT NAME:

Sales orders processing system (Jacks and Sons Suppliers: DD/MM/YY)

CURRENT PROBLEMS:

The following problems have been identified:

i) The sales catalogue for prices and products being used to process customer orders is often out of date.

ii) New items are not catalogued immediately and those dispatched still appear on stock lists.

iii) Records and orders are not properly done and there are problems with handling of customer enquiries.

iv) Back office orders are not always done and sometimes are forgotten about or misplaced by the clerks.

v) There is a large volume of documents flowing through the system besides order forms and invoices and this has also caused slowdown of the processing of order forms.

vi) The method of data storage makes it difficult for management to obtain useful information and this is making the decision making process slow and it is difficult to strategise.

OBJECTIVES:

To investigate initially, the feasibility of computerisation of the orders processing, invoicing and stock system.

Constraints:

The entire project is to be budgeted for completion within 8 months at a cost of $950m.

Plan of Action:

- To investigate fully the existing system especially the sales orders processing area, invoicing procedures and the warehouse (stock control).

- To further investigate the feasibility of a computerisation system as a solution together with estimated costs.

- To produce a report of the feasibility of the solution within two weeks, together with a budget.

The existing system is easier to understand if the analyst produces a flow diagram of the organisation showing all departments and how they are related.Fig. 2

CUSTOMER

SUPPLIER

Fig . 2

Dotted line …… shows warehouse. Arrowed lines show links between different departments

Flow block diagrams show the most important subsystems in the organisation and they are a good overview of the current system which needs investigation.

Organogram charts also assist as they can be a reflection on the roles and relationships within the organisation e.g. who reports to who and how many personnel are found where etc. Most organisations post these charts at the

Order processing Accounts

Stock Control

Packing and Dispatching

Purchasing

Sales and Marketing

reception or are kept in the manager’s office. They may also be in the organisation’s documentation booklets. Part of the organogram for JSS is as shown in Fig. 9

- The hierarchical diagram shows the flow of control in decision making and levels of management activity.

- It makes it easier for the analyst to identify key personnel that may be necessary for an interview or to fill questionnaires or areas where observations can be conducted or where to collect documents for sampling depending on the information gathering technique the analyst may want to use, during further investigations.

- The analyst’s questions may boarder on the following for each department:

a. inputsb. proceduresc. outputsd. controlse. storagef. staffingg. cost involvedh. potential for growth

The main purpose for investigations is to establish the feasibility on the introduction of a computerised system as a solution. The investigation will also estimate likely costs and benefits of the proposed system and the feasibility report will concentrate on three main areas i.e. economic feasibility, organisational and technical feasibility looks at such things as cost benefit analysis i.e. benefits should justify the costs.

1. Economic costs will include SAAD costs i.e. analysts costs such as transport, phone bills, hotel bills, hourly rates etc.

2. Hardware costs.

3. Software costs.

4. Training costs.

5. Installation costs e.g. new buildings and offices, or partitioning of the existing offices may be necessary, network cabling, air conditioning , surge protectors and power generators in the event of power cuts , CCTV (common in most parastatals and banks in Zimbabwe) etc.

6. Commission and change over cost e.g. people may need to work overtime through loading data from the old system onto the new system .7. Redundancy costs e.g packages for employees that have been retrenched.

8)Operating costs: Hardware and software maintenance, power supplies, video films, stationery e.g. diskettes, paper, ribbons, cartridges and personel costs e.g. computer centre staff.

Economic benefits:

Most economic benefits are non-measurable e.g. savings on labour costs ie lower overtime bills, benefits due to faster processing e.g. faster debt collection, better stock control, better decision making facilities , better customer service, low error levels and better job satisfaction.

Technical feasibility:

Technical feasibility studies the possibility of a technical solution. It might look at the following:

1. Ruled governed tasks are easy to computerise as they are highly structured e.g invoicing, stock control , calculating salaries. Unstructured problems e.g. predictions of market tends , budget focasting , predicting economic future are difficult to computerise. |Nowadays new systems known as expert systems can to some extent of accuracy handle unstructured problems.

2. Repetitive tasks are easier to computerise e.g calculation of salaries or recording of stock into the system.

3. Complex tasks can be broken down and be computerised e.g a sales orders processing system can be broken down into :

i) Customer orders processingii) Credit control processingiii) Invoicingiv) Packaging and despatching.

4. Situations that need speed of response can be computerised e.g customer inquiries.

5. A database whose elements are used repeatedly for different tasks can be computerised e.g customer details are needed for:

i) processing an official company order form from details supplied on the customer order form.

ii) credit controliii) invoicingiv) dispatching goods

Organisational/operational feasibility

Looks at such things as:

1. Is the organisation likely to accept information technology as a solution to the current problems. Most African governments have not been giving computerisation the priority deserved. This can be evidenced by the archaic equipment still in use such as old type writers which are even worse off than obsolete word processors, for document processing. Even organisations with links to governments like some parastatals and banks are legging behind in information technology. In most developed countries , information technology has wide use in government departments such as the army and police departments. The Swedish government has from the beginning of this year (2006) informed all stake holders, that all transactions with the government would be electronic. Every stake holder has been advised to supply the government with a bank account through which such transactions like invoicing or payment of benefits, like government pensions or any other payments would carried out electronically (EFT). Physical cheques and invoices would be abolished in the near future. That way the government will save over $US150 million annually.

2. Incompetence of personnel, even after training . Most company executives are old guards who may resist drastic changes in business re-engineering. Elderly users may not be prepared for retraining and / or redeployment to other areas or departments.

3. Autocratic management will be sceptical of computerisation, which may result in decentralisation leading to loss of power and influence.

4. Computerisation may have negative or positive effects on salary

structures.

The feasibility report has the following sections:

Title Page: Name of project, report name, version, author, date.Terms of reference: These are extracts from statements of scope and objectives (DP)Background: Background of the current system , current problems ,reasons for a new system and organisation’s development plans for the future.

Methods of study: These are details of investigation including personnel interviewed , documents looked at or sampled , areas that were observed , respondents to questionnaires and problems that were encountered during information gathering.Present System: This is a statement of the main features e.g. major tasks, staff, storage facilities and any current equipment, procedures and relationships with any other sub-system in the organisation..Proposed system(s): Outline of the proposed system (s), feasibility of each( economic technical and organisational feasibility).Recommendations: An indication of recommended option and reasons why.Development plans: Schedules of stages including gantt charts and project costs for each future stage in the system life cycle.Appendix: This is supporting material to main report. An appendix mayl be a sample of questionnaires that were responded to or summaries of interviews conducted. They can be gannt charts, quotations of software and hardware or copies of sampled documents. It can be anything to assist in making the feasibility report clear. (see appendices at the end of the module)

Process analysis and Modelling

Systems Analysis

Systems analysis assists to ascertain what must be done to meet the functions of the system.

- It involves the decomposition of the functions of the system into their logical constituencies which will result in the production of a logical model of the processes and data flows.

- Use is made of data flow diagrams and the different algorithms of the functions of the system can be presented in the form of structured English, decision tables and logic flow charts.

- It is important to carry out an analysis of the flow of documents between process and different departments as a first step.

- Deficiencies and controls with current system are also analysed.

- Tools used during the stage of analysis can be presented as below:

Logical DFDsModel LOGICAL Structured English

MODEL Logical Flow ChartsData Dictionaries

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Physical Manual SystemSystem Physical Description Flow charts

Manual System Flow Charts

Manual system flow charts uses the following symbols:

1. Flow line – this line shows direction and sequence of flow.

2. Indicates a manual operation e.g. batching of order forms, batching of invoices, filing of documents.

3. Indicates a document e.g. an order form, invoice, acknowledgement note etc.

4. Shows manual storage e.g. cabinets where order forms        are stored, box files where loan invoices stored,

cardboard                box where time sheet forms are stored.

5. Represents input/output e.g. the place where documents enter/leave the system.

6. On page connector. Manual system flow charts might be done on                       2 or more pages.

7. Off page connector.

8. Sorting activities.

E.g sorting delivery notes according customer addresses or invoices according to dates or amounts for the purpose of debt collection

- The chart is divided into vertical sections representing different location for operations. (see fig. 5)

- The chart proceeds as far as possible from left to right and top to bottom.

- A far left section can be reserved for brief explanations.

- Documents are shown at the origin and at entry into sections to avoid confusion with other documents.

- Ensure that all documents flow in the system are accounted for e.g. by permanently filing them or by being destroyed or leaving the system or being transferred to another part of the flow chart.

Accounts

Invoces

customers

Ass : Considering the above guide lines , make necessesary adjustments to Fig 5. What operational changes can you suggest as an analyst?

Manual system flow charts have the following merits:

1. They are easy to understand and assimilate. They assist the analyst to fully understand procedures and sequence of operations.

2. Shortfalls in document flow are picked up and this may necessitate further investigations.

3. Little technical knowledge is required to construct the chart.

4. Chart can be used as a communication tool between users and the analyst.

5. Shortfalls and controls, duplication of duties, bottlenecks are easy to pick out.

Demerits

1. Heavily integrated systems may produce complex flowcharts which will need lots of paper and thus there is less usual impact.

2. Manual systems flow charts are difficult to amend.

3. Important informal information might not be incorporated.

- Flow charts may also help management to set up uniformity of operations at different branches/organisations.

- They may also be used for internal auditing purposes and evaluation of the system. They may also act as user manuals.

Manual flow chart for Jack and Sons.Fig: 5Customer Credit control Accounts

Accumulation of Order forms

COF Customer order form

Invoices to Customers Batching of

order forms Invoice

COF

Checking of prices

Data flow diagrams

- Assist in the building of the process model. DFDs are independent of physical details unlike manual system flow charts.

- They show the various flows of data between processes that transform the data.

- They also show data stores and the points at which data enters and leaves the system.

- They have the basic following basic symbol.

1. – shows source or sink of data.

2. - shows data processing

3. - shows a data store

4. - shows a data flow.

- A data process is one that transforms data and the process may be manual or a partially computerised process or may be a computerised process.

CASE STUDY:

Sales orders processing DFD for JSS (High level diagram)

Fig: 6.

Goods catalogue Company order forms

Price catalogue Orders Customer order forms

Processing Customer details Suppliers details

Dispatch Invoicesnotes

Sales ordersProcessing

Credit Manager

Customer

CUSTOMER

unapproved orders , dispatch notes forms invoices

Ass : Can you briefly explain what is happening in the above high level DFD ( Fig 6.) As an analyst can you suggest a more efficient way of doing business for JSS and then draw a high level DFD showing your suggestions.

- A data store shows data that would be retrieved e.g. on a magnetic tape, disk or physical file.

- A DFD looks only at functions that are carried out and ignores the locations of those processes and who carries them out except where these appear as a sink or source.

Fig 7Customer c/o c/d CustomerOrder 1 details

Generate Credit unapproved order Company original Manager Order customer orders

Price catalogue aco Approved company orders

checking stock Invoicing

Goods Goods details Process Dispatch notes Dispatch& 3

acc invoiceDetails Stock packaging Process

Control invoiceSuppliers sd (Ware House) (Accounts)details 2 Dispatch note

Customer Invoice The DFD for the order

The DFD has got the following:

1. Sources/Sinks

a. customerb. credit controlc. packaging and dispatch

2. Processes

a. generate approved company orders

b. process stock controlc. process invoices

3. Data Stores

a. goods detailsb. price cataloguec. customer detailsd. company orderse. customer ordersf. invoicesg. dispatch notes

4. Data Flows

a. customer orderb. company orderc. price detailsd. goods detailse. customer credit detailsf. invoiceg. customer invoice

question : Can you modify the lower level DFD for JSS showing the changes you suggested in Fig 6 .

Data flows and data stores are specified and will be necessary to the file and data base design. Data elements will be presented in a tabular form and in detail e.g. company invoices have the following details such as:

- invoice number- customer name and address- order number- item number- price- subtotals and total

- discountsThe same should be done with

1. Company order5. Dispatch notes6. catalogues7. customer details etc.

- These details should be explained and recorded in a data dictionary.

- General guidelines to a DFD.

1. Identify the major process

2. Identify the major data stores3. Identify the major data sources/sinks4. Identify the major data flows5. Name the data flows, processes, sources, sinks and

stores 6. Draw the diagram

7. A DFD should have a limited number of processes for it to be clearer.

- Logically related processes can be grouped into one.

- It is advisable not to have more than seven processes on one DFD.

- The combined processes can be exploded on another DFD of a different level and this is part of the top down approach.

- A DFD can be summarised as an important tool of SAAD that ensures that the top-down approach is taken. This promotes logical as opposed to physical view of data flows and processes.

- Eventually the data store may form part of the file structure or the data base of the new system and data processes may become programs or subroutines.

- The flows will correspond to data passed in and out of programs and to or from the data base or file structure.

- The levels of DFD shows the level of top down decomposition that will allow management and users to understand the system as DFDs are non-technical therefore a good DFD is a powerful communication tool.

- Data dictionaries (DD) provide information about the structure and use of data in the organisation and it is therefore very much connected to the DFD.

- Part of a data dictionary might be as below:

NAME: TYPE:

INVOICE: DATA FLOW:

ALIASES: Customer invoice Client Invoice Ware house Invoice

STRUCTURE:

Aggregate: (Invoice number, date, customer number, customer name, item number, price, discount….)

Usage: CharacteristicsOutput process number 3Input sink – AccountsOutput sink – Customer

Input sink warehouse- DDs provide precise specifications of data elements.

- They are used right through the process of analysis to detailed design.

- DDs can be computerised and are thus referred to as encyclopaedias.

- DFDs together with process specifications and DDs are part of the logical model of the systems.

- There are special business conditions that may not be included into the DFDs e.g. calculations of discounts or other special favours to chosen clients.

These conditions are shown in a table known as the Decision Table (DT) e.g if the organisation has discounts for the following conditions:

a. Orders above $1millionb. Delivery within 60kmc. Customer turnover of above $60million.

A condition is either satisfied or not , ie it can be yes or no.These above three conditions can be presented in a table and therefore the maximum number of conditions possible will be 23. Therefor the DT can be presented as below. Fig 8

This table is refered to as a Limited Entry Decision Table. Some more complex decision tables include what are known as Mixed or Extended entry Tables. (research on them).

Question : Can you sugest your own business conditions that may be recommended for JSS to enhance retaining of clients who are running away and show them in a decision table. (More than 3 conditions) see sithole dt)

Fig 8

Decision Table

1 2 3

Free delivery within 60km

5% for orders above $1m

10% for turnover ›$60m

Free delivery

5% off 10% off

0 0 0 N N N - - -0 0 1 N N Y - - Y0 1 0 N Y N - - -0 1 1 N Y Y N Y Y1 0 0 Y N N Y N N1 0 1 Y N Y Y N Y1 1 0 Y Y N Y Y N1 1 1 Y Y Y Y Y Y

- Decision tables are also non-technical and are thus a good communication tool that will assist in the understanding of business processes.

- Business decisions as discussed above will be incorporated in the program during programming thus automating the decision making process. ( check your programming tools for logical functions OR, NOT <NOR AND NAND, < > => =< = not= etc)

- Decision tables assist in the complying with company policy in as far as taking different actions in different conditions.

Advantages of DT

a. Provide a clear tabular representation linking conditions with actions and thus act as a communication tool.

b. Ensure exhaustive coverage of all conditions or possible cases.c. Can be used to investigate inconsistency.d. They are easy to follow on operation.e. They can be easily incorporated into programming specifications e.g.

through use of such logical functions as discussed above.

Disadvantages

a. A large number of conditions will result in a large table which will make it difficult.

b. Decision tables are only suitable when a few actions need to be undertaken after evaluation of a set of conditions.

- If a decision table becomes cumbersome it becomes easier to use LFC as part of the logical model. LFCs use the following symbols

Process order

stop

Offer discount %

Offer discount %

Flow line

Starting or termination of flow chart

Process

Decision

START

CLIENT Y WITHIN 60KM

N

Transaction Y Over

$1m N

Turnover over $60m Y

N

Question : Draw a logic flow chart for the business conditions decisions you suggested for JSS in question no--

Offer discount %

STRUCTURED ENGLISH

It is another tool which may be used to explain processes within organisations. Structured English is also precise and encourages structured programming. It avoids use of irrelevant words when describing process.

Structured English makes use of reserve words to show the logical structure of a process e.g the structure IF THEN ELSE to describe a two way decision. Use ismade of short and precise sentences and phrases. There isno standard Structured English but all usages have common features. Long sentences are avoided. Eg PREPARE COMPANY ORDER FORMS (COF) ensuring that all details from original customer order are not missed.

This sentence can reduced to:

GENERATE PRECISE COF.

Names of data items should be the same as those on the DFD , DT,LFC or DD. Some reserved words are used in Structured English eg IF THEN ELSE , CASE ,ENDIF, ENDDO, START, REPEAT, WHILE, END ,STOP

Any process can be described using these three structures:

a) sequential structureb) decision structurec) repeatation structure

These have been dealt with in such modules as Introduction to Programming and thus will be discussed in brief.

An example of sequential structure will be as follows:

a) Compute Gross equal to hoursworked multiplied by hourlyrateb) Compute Tax equal to Gross multiplied by 30%c) Compute netsalary equal gross minus Taxd) Print Payslip

start

a

c

c

d

stop

Decision structures deal with conditions. Eg a certain action has to be carried out after a decision has been satisfied or not. The structure can be two way or multiway.

A two way decisi0on can be handled as follows:

IF <condition> THEN < action-1> ELSE <action-2>ENDIF

Eg IF client is new THEN create new account ELSE process COF ENDIFOr

IF Invoice_Total > 100million THEN process 30% discount ELSE no discount ENDIF PRINT Invoice

Case Structure

A multiway decision can be handled as follows:

CASE <variable> CASE1 <value1> DO action1 CASE2 <value2> DO action2 CASE3 <value3>o DO action3ENDCASE

Repetition structure:These are used where a process is repeated until a condition is met.

condition

Action1

Action2

Value1

Action1

Value2

Action2

stop

Value3

Action3

Repetitions can be handled by the structure DO WHILE <CONDITION> END and REPEAT

EgDO WHILE <condition> N

ActionEND y

Or

REPEAT DO action UNTIL <condition> N

Y

Eg DO WHILE credit_limit > order_total GET next order_amount ADD order_amount TO order_total

Statements may be nested and loops may be terminated by such phrases as ENDIF,ENDDO, ENDCASE etc

Data Analysis and Modelling

DFDs shows the data processes and flows of data between these processes but does little to represent the contents of the data stores i.e data stores are not elaborated on DFDs.

- Nowadays most business information systems are integrated and therefore the analysis and design of databases is an important stage in the life cycle of the system.

- Data models can be used to design an effective database.

A bottom up approach in designing a data store may involve extracting data fields as they appear on the physical documents such as invoices, order forms, dispatch notes, receipts, time sheet forms etc.

Actioncondition

action

condition

- The data elements on these documents are then grouped into records e.g. an order form can be converted into a record with such fields as order number, date, quantity, item codes etc.

- These records make up a file structure and a collection of these files make up the order file of the organisation. This bottom up approach may work for small systems which required little/no internal integration.

- However, this will not be efficient if there is a large number of fields which are to be shared among different applications or subsystems.

- There will be potential repetition of the same field, thus resulting in an unnecessarily large database characterised by inefficient updating of records and also slow records access time.

- Such limitations can be avoided through use of the top down approach in data modelling. The approach uses the logical rather than the physical structure of the database as a first step.

- The data structure for any organisation remains constant though the functions on it change with time e.g. reports needed from the same data change with time.

- Data modelling involves entity relationships. An organisations data structure can be based on entity relationships. An entity EMPLOYEE on a payroll system will keep such data as employee number, date of birth, rate, department etc.

- The entity ORDER will have such data as order number, customer number items etc.

Entity types may have relationships e.g. the entity EMPLOYEE will have a relationship with the entity DEPARTMENT because each employee will belong to a department. Not all entities will have a relationship with other entities e.g. entity ORDER has no specific relationship with entity EMPLOYEE. The relationship between an employee and department can be called membership.

- Each relationship would have a unique name that tries to explain that relationship and the relationship between entities in an organisation form an important feature for that organisation.

- Entities also have attributes e.g. the entity EMPLOYEE will have such attributes as employee_number name, date_of_birth , department, rate, grade etc

- Each entity has a clear attribute e.g. each employee will have an employee number, therefore entities, relationships and attributes can be regarded as one way of looking at the organisation.

- In the computer system to be developed, the entity type can be represented as the record type and the attributes will be the field of that record.

- The attributes can be looked at as fields of that record.

Types of relationships

- There are several types of relationships which will include the following.

a) 1 : n relationship

Department Membership Employees

- Each department has several employees as members and each employee belongs to one department.

- If there is a department without a member then below

Department Employee

- If there is one member without a department

b) m : n relationship

Suppliers

e.g. an item in the stores department can be supplied by many suppliers and each supplier can supply many items.

c) 1 : 1 relationship

Summary of data analysis and modelling

The analyst defines major data areas to be covered by the model i.e. he determines the major functions of the organisation e.g sales orders

suppliers item

Employee Department

item Supplier

processing, marketing, accounting, purchasing, inventory and administration etc.

2. He develops a data model for each and may later amalgamate those models e.g. if dealing with a complex organisation.

3. He selects the most important types of entities and lists them including their attributes.

4. He determines relationships, their formats and gives them appropriate names.

5. He then builds entity models which will form the entity diagram.6. Entity models are amalgamated into an entity model for the

whole organisation.7. The adequacy of the entity model is tested against the functions

and processes required of it.

Data that is required for the functions and processes for the organisation has been established during process analysis and modelling. DFDs, SE, LFCs and DTs give a clear picture of what data is required. Data analysis should ensure that all data required and its attributes is represented in the data model. The model should have paths through which data can be extracted e.g. suppose that the process of reordering an item is a function that is to be automated ie everytime an time reaches reorder level in stock, the function is automatically triggered. It might through a flashing message or an alarm. The function will also include downloading all previous suppliers. In order to carry out the application, a list of suppliers of that item should be available to the process. Therefore the entity ITEM should be connected to the entity type SUPPLIER through the relationship suppliers. Through the key attribute item_number, it is possible to retrieve all suppliers connected through the relationship as shown below:

Suppliers

Suppliers

Item Item number

Re-ordering (function /application)

In the CASE STUDY of JSS, the major data areas the analyst discovers are, sales orders processing system – purchases orders processing system, stock control, dispatch and scheduling. He has to restrict himself to the orders processing system as this is the problem area. He then selects important entities types for the chosen data area and these can be as listed below:

Customer

InvoiceCompany order, customer orderItemsDispatch notes

Some entities can be removed e.g.the entity CUSTOMER ORDER will have details that will be transferred to the company order and as a result one entity remains and called ORDER. The analyst has to ensure that all the information from the customer order is transferred to the order. He will end up with the entities CUSTOMER, ORDER, ITEM, DISPATCH NOTE and INVOICE. He then determines attributes and the key attributes which may be respectively customer number, order number, item number, dispatch note number and invoice number. He then determines what relationship exist in the entities types. These relationships can be established during the process of information gathering e.g. during interviews with the employees processing the orders or invocing or in the ware house e.g. a customer may place several orders but each order can be placed by one customer only, therefore the relationship is I:N. Each order requests many items such as computers,televisions, radios etc. Each item can appear on many orders therefore the relationship is M:N.

- The summary of relationships is shown in a table. Each relationship has a meaningful name. This is necessary because there may be many relationships amoung entities and therefore they should be distinguished.

- The analyst builds the entity models. (draw page 388)

- The dotted connections on the relationships especially those connected to the entity ITEM shows that there is a possibility that the items are not yet in stock and therefore not yet invoiced and dispatched.

- This is a recognition to the fact that time delays can occur between placing of an order and dispatch.

- The analyst then decides on the attributes of each entity.

- These attributes on the entities are then fine tuned/normalised. (to be discussed in brief later)

- Separate entity models are amalgamated into a single entity model for the organisation as a whole thus the analyst ends up with a single data model.

-

- The analyst will then construct data models for the other major areas besides the sales order processing area e.g. stock control area, purchases orders processing orders.

- ASSING : Add the purchases area to the sales ER

- He may then amalgamate these separate areas if he is going to computerise all of them. Adequacy of the entity models is tested against functions and processes required of it. Thus the data model will form basis of the design of the database.

- In conclusion the process model and data model will become the basis of what the analyst will design.

SYSTEM DESIGN

So far we have studied how analysis proceeds from the collection of descriptive material on the functions of existing physical system right through to the analysis of the logical model of that system.

- Data flows between processes were defined and analysed using DFDs for various levels.

- Data processes were specified using DTs, LFC, SE and a conceptual data model was derived.

After these stages the analyst can now move to the next stage which is design.

- The initial task before, engaging in designing of the system is to remove any physical aspects that may have into crept or have been incorporated into data model and also some business activities that may not be very logical but have been inco-operated data model and also there may be additional requirements that management, users and the steering committee may want inco-operated in the new system(examples of these are explained a bit later). This therefore will mean construction of the new DFD and subsequently new ER models and thus a new data model, which can now be used as the basis of the system design.

- At this stage the extent of computerisation will be determined , together with manner in which different processes on the DFDs are to be carried out e.g which ones will be in batch mode as distinct from on-line or real time mode.

- Decisions are also made on whether the system is going to be centralised/decentralised/distributed.

Decisions are also made on whether the system is going to be a file based one or data based system . This is system design and all these design options should be clearly outlined for the consideration of the steering committee

and management as each design has schedule, efficiency and direct budget and financial implications.

The sytems analysts then presents 2 or 3 designs which will then be presented to management and steering committee for assessment. (Due to time restrictions students doing project 1 (hscs 208) normally ignore this part).

As soon as one alternative is accepted then detailed design commences.

Transition from analysis to design has been looked at above and has been seen to be dealing with limitations which may have crept to the logical design of the current physical system. Some of them may be as below.

a. There may be new requirements for the new system, that are not being satisfied and they have to be put into consideration.

b. Inefficiencies in the new system may be translated into the logical model. The model should reveal the logic of an efficient system and therefore there should be necessary amendments.

c. It is often the case that physical aspects for the existing system also creep into the logical model and these should be removed before designing systems.

- New requirements can be obtained through interviewing management and users therefore the logical model should be amended to accommodate these new requirements.

- DFDs are then amended as the new processes and data flows are added.

- Entity diagrams are also amended e.g. management in Jack& Sons Pvt Ltd realises that it was difficult to derive useful management information like figures on goods sold. They may want the new system to generate a sales analysis report and this is an extra process that was not on the initial DFDs constructed at analysis stage. This process to be incorporated in the DFD might be as shown below:

Customer details Credit notes details

SalesGoods details Analysis Sales and Marketing Manager

Process

Invoice details

The indicated data stores are necessary for the sales analysis report.EXERCISE can you identify new data flows , sources , sinks.

Can you incoporate this portion into the old DFD derived at analysis level?

Functional entity diagram for this process can be as shown below:

Customer details Invoice details

Invoice

Item

Sales analysis processing

- The entity customer will have such attributes as customer number, address etc.

- The entity invoice will have attributes as customer number, date.

- Entity invoice details will have item number, customer number, quantity, price.

- Entity item will have item number, item description.

For any selected invoice it is possible to retrieve customer details, invoice date, invoice total through the relationship of customer invoice and for any invoice it is possible to get further invoice details through the entity of invoice details and it is again possible to retrieve item details through the relationship invoice details and item therefore it becomes simple to produce sales analysis report.

Adjustments should be made to remove any other efficiencies e.g. in the case study of JSS the procedure of dispatching dispatch notes which was happening immediately after receiving a customer order could be better done after the process of credit control and only the clients with approved orders would receive acknowledgement notes to save postage costs.

- It is also possible that the logical model has one data store containing such documents as invoices, company order forms, receipts and acknowledgement notes. This could have been because these documents have been kept in the same physical file in the manual system for reconciliation purposes.

- Putting all these documents into the same data store in the logical model is an example of inefficiency.

- All these documents should be stored into their own individual data stores.

It may be advisable to copy and paste your DFDs done at analysis stage as your entrance into the design stage so that the new requirements from users to be are much more clearer shown. ( Most students will want to simply design a system strictly as per the existing physical system. They try to avoid introducing new requirements or improving on the logics of the current system. This is bad systems analysis as there is rarely a new system that will not have new requirements or improvements on the current logics. So for your project HCSC 208 you are advised to observe this, for better quality work). EXERCISE : Construct a DFD for the registration process you under went at level 1.1 and suggest any new requirements or improvements for the model before it passes on to the design level.DESIGN ALTERNATIVES

- The analyst has to suggest 2 or 3 alternative designs and this is referred to as SYSTEM DESIGN.

- Management has to select one of them, after which the analyst embarks on detailed design.

- Alternatives have been suggested and costed during feasibility studies but the analyst at this stage has a much greater understanding of the new system than earlier.

- There may be new opportunities from what is previously understood and these may be incorporated into the design.

- The logical model will assist the analyst in presenting the alternative designs to management.

- There will also be decisions on the extent of computerisation, which processes the process model will be computerised and which will remain manual. (automation bounderies).

- Decisions also have to be made on the type of system to be produced e.g. is it going to be centralised, decentralised, distributed, file based or database based. (Most students ignore this stage and lose marks. You will be advised to highlight and weigh the advantages and disadvantages of each of the above design type and justify which of them you would opt for.)

There should be also discussions on which process would be batch or online, input methods e.g. use of keyboards, digital cameras, bar code readers, MICR , OCR etc.

Management also decides on whether to buy a suitable application to meet the demands of the different processes on the models or whether the processes should be programmed/coded by internal/external programmers (software houses).

Decisions should also be made on how to acquire the most appropriate hardware and auxilillary packages e.g operating system platforms (Windows 98 ,xp, nt, linux ,open vms ,unix etc), back up packages , antivirus software and other utility programms.

Automation Boundaries

Automation boundaries show the areas that have been chosen for computerisation and these have to be agreed on by the management.

- The analyst should limit his alternatives to only 2 or 3 as many more would confuse management.

- These alternatives will show extent of computerisation e.g. a low cost system will be one that will satisfy the basic needs of the project whilst onether can be of medium cost and it will incorporate few extra opportunities.

- A system can be designed on a grand style where there is exploitation of the full benefits of the computerised system e.g including and integrating sub systems like account, stock control, purchasing, marketing,e-mail/internet facilities, use of OCRs and acceptance of credit cards, purchases through the internet , use of digital cameras , scanners etc.

Exercise : For your MSU students registration model , can you show the automation bounderise that were in place where you joined the institution and changes that have taken place since then to date. Can you suggest further changes that may need to be taken into consideration in the future for a grand style system?

- For each of the alternatives the analysts should provide estimated costs, time schedule for the completion of the project and he should always maintain a clear idea of management constraints and objectives of the organisation all the time.( Due to time constraints most students ignore this, they assume costing done at feasibility studies stage will suffice. There should be a more accurate costing assessment at this stage as the picture of the system is much clearer than before.)

- Suggested alternative alternative systems are presented to management at a structured formal review, where management will select one and then give a go ahead. (It is advisable to conduct such

reviews off site where there is little disturbance. Most companies prefer to hire conduct it in quiet boardrooms or hire conference rooms available e.g at selected hotels)

- The analysts may wish to present aspects of his work this way through out various stages of the project, and can do this through walk throughs, demos and ask for feedback from his audience all the time.

Detailed design implementation and review

- It was seen how the analyst uses logical model of the system to suggest alternative designs for the new physical system. Decisions were made on the overall extent of computerisation and types of systems that could be developed.

- Having obtained agreement from the relevant management, the analyst must now carry out detailed design for the new system. This will include specification of hardware, software, database or file systems structure, user interface and time schedules for the completion/implementation of the project.

This detailed specification, is the document from which the system will be built and once agreement has been obtained for the detailed design ,steps will be taken to acquire hardware, its installation writing/coding of the software or purchasing of the software. The database or file structure is created followed by thourough testing of the system through use of test data. Training of staff and documentation of the system is an on going process as shown in the Gannt |Chart. The next stage will be converting to the new system and loading of the contents of the existing files.

The system is now ready to take over from the current one. After change over a post implementation review considers the effectiveness of the new system and its vis a vis the initial specifications and objectives of the organisation.

- Finally, ongoing maintenance and development will ensure the continuation of the lifecycle of the system.

- Process design

- Process design deals with the specification of hardware taking into consideration the different software that is going to be handled by the CPU and RAM. The analyst has to understand the amount load to be handled by the hard ware e.g volumes of transactions per given time, the type of response time e.g when running queries or enquiries or reports. He has to be aware of the number of users logging on to the system simmultanciously and the potential for growth.

- ( A lot of students can not justify their choice of hardware. There has been dramatic changes in CPU technology since the early 1980’s when

intel chips i8080 followed by i80280 , i80380 , i80480 (mid 1990’s) which where then followed by Pentium technology (from late 1990’s) , Pentium 1 ,2,3,4 to date. These processors have different processing powers and can support different different amounts of RAM. Operating systems are also developing fast and will keep on demanding fast and powerful processors and that’s why a micro processor generation fast becomes obsolute.Windows operating systems are the most popular and mostly widely spread products which are changing at a very fast rate. Microprocessors up to Pentium 2 products have become obsolete because they cannot comfortably meet the demands of these latest windows products eg windows xp together with the new software and auxiliary packages for the new system. It is therefore advisable to suggest the latest available microprocessor if the budget allows as this will cater for the rapid changes and also the growth potential. If this is not carefully handled , a new system will soon fail to handle an increase in the volume of business transactions or the number of users logged in at any given. In such cases , the system will start to freeze (hang) frequently resulting in user frustration. There is one such system at MSU.)

-- Besides the CPU and RAM process design also looks at other

peripheral devices such as printers ,screen types , modems ,scanners etc which not be the cause for bottlenecks during processing e.g fast processing will need fast printers like laser printers or quality production processes like graphical systems will need coulor screens with a high pixel value and quality colour printers. NB it will be useless to recommend a colour printer for a library system or stock control system as that will be an unnecessary expense. If the new system is going operate in a wide area network envinronment and needs to work in a real time mode like most banking systems , then it may be necessary to recommnd data communication technologies that can handle a wide frequency bandwith e.g opitic fibres or sattelite communication.

- Program specifications

- Program specification can be obtained through structured tools elaborated at analysis stage( DFDs’ SE, LFC). These tools show individual modules that are going to be the basis of an integrated system. They can be constructed independently before integration as they perform independent functions. It is also easy to intergrate new modules or remove some eg just before design stage as explained earlier.

-- Connections between modules during intergration should handled

carefully in the sequence of the logics of the processes. This can be illustrated with the assistance of a structured chart as shown below.

- A module contains a set of executable instructions which will be performing a certain process and thus the connections have to be designed carefully as the modules will be passing data from one to the other. This can be illustrated with a structure chart or IPO chart. See fig

- The modules can be coded using a chosen language e.g. C, Pascal, VB or CTT.

- An example of a module which is part of a payroll processing a payslip is called PREPAYER PAYSLIP.

This module will call for several other modules:

a. GET EMPLOYEE DETAILSb. GET TIMESHEET DETAILSc. COMPUTE CURRENT SALARYd. COMPUTE SALARY YEAR TO DATE

- Module C may also call more sub-modules e.g. compute gross salary and compute tax.

Structured chart

The structured chart can be presented as an IPO chart (Input-Process-Output). The IPO chart can be as shown below:

System Payslip Processing

Prepare payslip

Get employee details

Timesheet details

Current salary Salary year-to-date

Compute taxGross salary Compute other

Module Name Prepare Payslip

Author Chipfumbu Colletor TDate 09/11/04

Module Calls Get employee DetailsGet timesheet detailsCompute current salaryCompute year to date

Module called by Prepare payslip

Module Inputs Employee numberTax table

Module Output Gross salary, payee, net salary, salary V.T.D

Processes Do get employee detailsDo get time sheet detailsDo compute net salaryNet salary – gross payTaxCompute year to date

- All the inputs and outputs should be elaborated in the data dictionary.- EXERCISE Try question no in question paper no 2006 (Do the IPO as well).

- Such modular specification together with data dictionary is sufficient for the programmers to write a code using most appropriate programming language e.g. C, VB, COBOL, PASCAL etc.

- These modules can be programmed independently.

- The structured chart is a diagrammatic representation of the way the modules are connected.

- Each module shows what data is input/output and also what other modules call it or are called by it.

- If the IPO charts are presented in a hierarchical format then such charts are referred to as the HIPO technique.

Structured charts are closely related to structured English as shown below:

The three examples would be:

a. sequential processesb. reputationsc. conditions

Sequential :

which are expressed as;

Do block ADo block BDo block CDo block D

Condition : IF <>THEN DO BLOCK B

ELSE DO BLOCK C

END IF

Repetitions:

RepeatDo Block BDo block CDo block DUntil < >

The modules may have sub modules and they are executed from left to right.

A

DCB

B C

A

B C D

A

B E H

C D

F G

The order of calling for a HIPO should be A B C D E F G H

Merits of modular design

a. It is much easier to design programs. The analyst may be able to specify major tasks at high level and later break them into their detail which is top down decomposition which is carried out at analysis level.

b. Modules are manageable.c. Individual programmers and designers can be given different modules

and work independent of each other.d. Project management, scheduling and designing, costing , and

allocation of manpower are made easier.e. Separate modules can be tested individually and errors are easy to

locate and correct.f. It is easy to modify or insert modules.

Data store design

This stage involves data models that have been constructed during systems analysis i.e entity models and ER diagrams and entity attributes. Normanlisation of entity models is dealt with in the course DataBase systems to be covered at level 2.1 and therefore students should be well equipped to handle data store design when they embark on their project (HCSC 208) at level 2.2 . NB most students do not show any normalisation of entity models and thus lose marks at design stage. A normalised entity model will ensure that various processes in the design will be served with sufficient data that they need.

EXERCISE : Highlight the advantages and disadvantages of file based data store and those of a database based system. What are the best hardware requirements for each?

What are DBMS?

Input/output design

Input/out design deals with two aspects of the system.

a) Hardwareb) User machine interface

Hardware details are determined at design level. The method of input and output of data and information determine the type of hardware to be aquired. E.g if the MSU students registration system is going to be grand style ,then data input hardware will include keyboards ,scanners ,mouse devices, digital

cameras for student pictures and this data store may also be shared by sub systems like the library system and clinic system, colour screens. Output devices will include keyboards , colour printers for student and library cards, heavy duty dot matrix printers for printing students result, laser printers for general office assistants reports .

User –machine interface will include screen input/output and also printed output. The design may depend on the type of the user to be. E. g the level of details on the input /out put screen may depend on the level of computer appreciation on the part of the user. In general user machine interface looks at the following:

a) Screen designb) Controlsc) User guidanced) Error messagese) Response timef) Reports and input documents

Screen layout should be such that there is little chance of errors during data input. This can be achieved through usage of menus to allow easy selection , form filling with the assistance of the curasor jumping from one field to the other as data is input and interactive commands e.g Please Input name ,Enter EC number etc. The font of text and screen back ground are also important. Some students design outrageous screens such that by the time they finish their presentation , the panellists are already suffering from sore eyes. Some will have text in bright yellow on a bright orange background.

Controls can be designed to minimise input errors. They include :

a) Batch controlsb) Codesc) Software controls

Batch controls will include inputing the batch total first e.g when capturing a bacth of invoice or cheques or receipts. Individual document details and values are then captured sequentially and added automatically until the last document. The total value of documents added by the sytem is then compared with the initial batch value and if there is a difference it means there was an error. The difference may be due to a wrong figure tha was captured or a document tha was skipped or the initial batch total that was input was wrong. So it becomes very eqasy to identify and correct an input error. This common in all accounts departments tha process documents in batches.

Software controls will include validation of fields eg a field can be designed to accept only digits and when characters are accidentally entered the screen rejects and warns the user of the error. A field may be designed to accept only dates eg DOB. and nothing else. Software controls may also include

calculating check digits eg when capturing national ID numbers or vehicle number plates.

Codes are used in most stock control systems to minimise caturing a lot of product details. Most supermarkets have POS that use bar code readers or simple product codes which will automatically retrieve full product description including the price on to the screen. This allows for faster and accurate processing.

User guidance is a screen design that should done for users who expertise in use of computers is very low. This involves assisting the user to be always aware of where he is in the system and what he can do at any level of the menus. That is the user can navigate his way around the different leavels of the system without getting lost. There help facilities at every level within the system.

A good screen design should also echo or display error messages in the event of errors in data input. Eg “ wrong date format” or “invalid code please re-enter” or “field can not be blank” in the event of a mandatory field not being filled during data input.

Response time involves designing a screen such that response time is minimal. Otherwise fast users may conclude that the system has frozen or may continiuosly repeat a command resulting in hardware problems. Very fast responses may also confuse inexperienced users.

Reports and input documents

Every system that is being design should have input and output which is a result of processed input. The design structure of input documents can be done with input from users to be. They will be related to input screen. The out put will include reports for decision making will be related to the objectives of the new system. The out output may be a print out (hard copy) or may be done on the screen. The design should done with the assistance of the targeted recipientc of the reports eg a sales analysis report should have input from the sales manager who will need the report, a finacial report should be clear to the finance manager and thus his input is vital. (NB for project HCSC 208 the student should have at least 4 or 5 reports that make sense and should be related to the project objectives. One student who had designed a flight registration system for an airport had a report simply recording the number of flights per day. When the panel asked why that report was necessary , the student said that the report minimised chances of managers stealing aircraft!!)

Reports may be periodic e.g monthly reports like sales analysis reports or debtors statements and others may be ad hoc eg account balances at any given time on request.SYSTEMS SPECIFICATION:

After detailed systems design ,the analyst should draft a document called systems specification document. This document is the final basis on which the new system is to be constructed. (For your project 1 (HCSC 208) this your final binding that should be presented to your respective supervisors for their approval before presentation of your system before your panels. This document is going to constitute 70% of your module mark. See appendix for the sub topics and mark distribution pertaining to the document.)

The document should have some the following:

a) A description of the proposed system and its objectives. The sustem should be described in the form flow block diagrams , DFD’s ,LFC’s , SE , ER’s etc.

b) Specification of propgrams through use of module specification ,structure charts (IPO/HIPO’s) and test data.

c) Descripiton of input including specimen of input source documents, screen layouts,menu structures , control procedures.

d) Description of output including specimen of out reports ,both hard and soft copies.

e) Description of data storage eg data base structure (tables and elaboration of their contents) or file structure.

f) Operation procedures and controls.

g) Description of all hardware needed to support the system.

h) Clerical procedures and responsibilities within the system eg user levels like ordinary users , administrators , system managers etc.

i) Detailed implementation schedule and training.

j) Revised cost estimates and constraints. ( Most students do not do this. They assume they have done this at Feasibility studies.)

The document is also important for the purpose of budget allocation for hardware acquisition and and be used for coding by programmers. It is also important as a permanant record of the system for future users or future modification of the system during its life cycle. The document is also used for systems evaluation ie checking how far the system is satisfying the initial objectives for which it was designed.

If this document gets management approval , then Systems Implementation may begin.

Implementation

Once the above system can be accepted and agreed on then implementation begins. Programmes are written and tested, hardware are acquired and installed. Staff training on the new system begins and the system is tested. Historic data from old files/from the old system is filed on the data database and all these should be completed before changeover is completed.

- Programming is one of the most costly phases in the system and normally it is completed late though structured techniques described so far have eased these problems e.g HIPO charts.

It does not necessaryliy mean that there should always be a programming stage. An application package can opted for at systems design stage if there is one on the market that can meet the design satisfactorily eg adopting a COTS ( Cusotmised Off The Shelve) package.

Hardware requirements have been included in the system’s specifications and the organisation might want to put to tender or the analyst may have the leeway of choosing the suppliers. Hardware can also be leased if the organisation cannot acquire its own.

Installation can be costly as it may mean renovations or building of new rooms that might need to be air conditioned and be dust free.

There may also be need to install physical security e.g. fire alarms , data communication and power cabling, video monitoring , secure archive rooms etc .

Training of staff

Users are key elements to any successful computer system and therefore they need to be properly trained if the new system is to be effectively used.

- There are several approaches that can be used to train users.

a. Lectures and seminars – advantage is that one instructor can train many members of staff.

b. Simulation of the work environment.c. On the job training (most popular).d. Tutorial software.e. Training courses.

Data Store Conversion

Computer held data is easier introduced in the new system because programs can be written to accept data from the old files or data base to convert it into the required format. Manual files can take more time to capture.

Change over ( check assignments)

Evaluation and maintenance

There is no computerised system which when once implemented remain unaltered throughout the rest of its working life.

- Changes will be made and maintenance undertaken.

- Hardware maintenance can be done through signing of contracts.

- Software maintenance will involve the removal of bugs that may be encountered as the system is used overtime.

- Techniques such as modular design structured programming documentation techniques and other tools discussed in SAAD will make the task much easier.

- There should also be cost implementation audit and this can be done by internal analysts/ a team of analysts that were not involved in the project.

- The audit considers these areas.

a. The adequacy of system documentation that governed manual procedures and company programmes.

b. Assessment on the training of personnel.c. Assessment on the reliability of output.d. Comparison of actual costs against those incurred during the

implementation of the project and significant variances should be investigated.

d) Response times will be determined and would be assessed and compared with those specified.

There is thourough assessment on whether the systems meets the original specified objectives suggestions on improvements are layed down for consideration. Some recommendations may be implemented immeadiately whilst some may be considered for the next phase of the sysem.

In short evaluation deals with such issues as efficiency , effectiveness ,security, and reliability.