MIS 2000MIS 2000

Class 20Class 20

System Development ProcessSystem Development Process

Updated 2015Updated 2015

Outline

• System Development Process

• System Planning

• System Analysis & Design

• System Construction, Installation, Testing

• System Deployment & Maintenance

• Good System Design

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System Development Process

Organizational goals & plans system needs to meet

Org. processes and data As-is vs. To-be

System solutions to problems in processes & data

Programming, purchasing software & hardware

Reality check

Fine-tuning the system as it is used

Plan System

Conduct System Analysis

DesignSystem

ConstructSystem

Deploy & MaintainSystem

Install & TestSystem

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System Development Process -Waterfall Logic

• System development steps can be run on the entire system sequentially in defined periods.

• Linear, finish one step, move to the next.

• If development time is longer, system may be obsolete at time of release.

Plan System

Conduct System Analysis

DesignSystem

ConstructSystem

Deploy & MaintainSystem

Install & TestSystem

years

0

1

2

X

4

5

• Never methodologies of systems development tend

be faster:

- develop systems in smaller parts

- each part develop quicker

- test the developed piece and move to next one

• Same development activities are performed, just with

different timing and in many cycles.

Business goals and plans to be accomplished with new system:

Optimize process designImprove process performanceDefine new processesWhat are the costs and financial returns expected from the process/IS changes?

How does IS in planning can help to accomplish goals above?

Plan System

Your ISIS you need

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• The goal is to understand the existing (present) business and systems (As-is) in order to create improvements (To-be).

• Focus on the present and…:

– Analysis of present organizational processes (design, performance) - interview end-users & managers.

– Analysis of present data (business documents, communications)

– Analysis of IT in the existing system

– In sum, analysis of informing needs and system solutions … and the future:

– System requirements – statements on what new IS should deliver

Perform System Analysis

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Conduct System Analysis

Analyze business &

IT/IS

Define System

Requirements=

Design System

• How will system requirements be realized

• Creating a new IS or upgrading the present IS.

• The data model is created or changed in case of upgrade.

• The processing of data in the system is defined according to the model of organizational process resulting from the System Analysis step.

• User Interface is designed (content and look of screens, & their sequence).

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STUDENT database

Construct System

• A system is physically made based on the design created (data diagrams, and process diagrams that determine what software should do – how the data should be processed).

• Options for acquiring software & hardware:

– Write application software (computer programs)

– Buy application software (off-the-shelf software)

– Rent application software

– Purchase computers and other hardware

Paired rather than individual programming is often practiced today as part of rapid IS development.

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Install & Test System

• Installation: Setting up a system into operation stage. Software is mounted on hardware, etc.

• Testing: Evaluating the performance of a developed system.

• Kinds of tests run based on moving from small to large :

1. Unit testing (system part, by experts)

2. System testing (whole system, by experts)

3. Acceptance testing (whole system, by users)

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System Deployment Methods1. Direct deployment

- New system completely replaces old one - Higher risk, lower cost

2. Parallel deployment– Old and new system used until the new proves reliable– Lower risk, higher cost

OLD IS NEW IStime

Old out/New in

NEW IS

OLD IS

time

New in

Old out

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Maintain System in Production Stage

• As IS is used and managed, its development continues in small - this is system maintenance.

• System maintenance includes:

– De-bugging software

– IS modifications based on business needs (e.g., enlarging data storage)

– Adding new software and hardware driven by vendors

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Good System DesignA well-designed IS system needs to:

1.Do the work it is planned to support – fit with business processes

2.Be easy to learn and use - user interface quality, menu design:

– intuitive screen items (labels, buttons; see MS Office screens below)

– screens reasonably complex (but ERPS not very good)

– letting users know where they are (navigation aspect)

– allows for easy tracking and correction of errors

3.Support efficient work - user interface & technical aspects. Impacts on process performance (timing, costs).

Drop-down menu design

Tab menu design

See Footnote

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Good design is goal but this might happen…

1 2

3 But…

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Good design is goal but this might happen…

1 2

3

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S u m m a r y

• System development process takes activities of planning, analysis, designing, constructing, installing, testing, and deploying, and maintaining an IS.

• Structural and newer rapid methodologies.

• Plan for new IS can aim at optimizing process design, improving process performance, and creating new processes.

• System Analysis focuses on both business and existing IS (if any) to understand how work is done and how it should be. System design creates new functions, data model, user interface.

• IS construction implements IS design physically.

• There are 3 methods of IS testing and 2 basic deployment strategies.

• System maintenance continues throughout the system use period.

• Well-designed IS performs work needed, is easy to learn and use, and enables efficient work.

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