Systems Analysis & Design (Sixth Edition) 1 Chapter 5 Development Strategies PHASE 2: SYSTEMS ANALYSIS

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Systems Analysis & Design(Sixth Edition)

Chapter 5Development Strategies

PHASE 2: SYSTEMS ANALYSIS

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Chapter Objectives

Describe software trends, including the concept of software as a service

Explain software acquisition alternatives, including traditional versus Web-based software development strategies

Describe software outsourcing options, including offshore outsourcing and the role of service providers

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Chapter Objectives

Explain advantages and disadvantages of developing software in-house versus other alternatives

Explain cost-benefit analysis and financial analysis tools

Explain the differences between a request for proposal (RFP) and a request for quotation (RFQ)

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Chapter Objectives

Describe the contents of the system requirements document

Explain the transition from systems analysis to systems design, and the difference between logical and physical design

Explain the transition to systems design and the importance of prototyping

Discuss guidelines for systems design

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Introduction

Chapter 5 describes the remaining activities in the systems analysis phase

The chapter also describes the transition to systems design, prototyping, and systems design guidelines

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Development Strategies Overview

Selecting the best development path is a key decision

Requires consideration of three key topics Impact of Internet Software outsourcing options In-house software development alternatives

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The Impact of the Internet

Software as a Service Software and Information Industry Association (SIIA)

- an industry group focusing on digital economy Software as a service - redefining the way

companies develop and deploy information systems How do you think software as a service is

different from software as a product? How might the concept of software as a

service impact the software industry?

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The Impact of the Internet

The Changing Software Marketplace Traditional S/W vendors develop and sell

application packages to customers New Marketplace traditional plus many forms of

outsourcing Application service providers Internet business services

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The Impact of the Internet On Systems Development

As an analyst, consider: Traditional Environment Web-based Development Development

IBM’s WebSphere Microsoft’s .NET

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Traditional development Compatibility issues Networks Web-based features are treated as

enhancements Security less complex than Web

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Web-based development Internet-based framework

.NET or WebSphere Treats Web as platform Requires middleware Limited in-house involvement, if desired Can prevent illegal copying

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Outsourcing

Transfer of IS services for a fee Performed on a temporary or LT basis Services

Development Operation Maintenance

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Outsourcing

The Growth of Outsourcing Traditionally

to control costs dealing with rapid technological change

Today Traditional reasons still valid Part of overall IT strategy

On Demand

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Outsourcing

The Growth of Outsourcing A firm that offers outsourcing solutions is called a

service provider Application service providers (ASP) Internet business services (IBS)

Also called managed hosting

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Outsourcing

Outsourcing Fees Fixed Fee model A subscription model A usage model or transaction model

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Outsourcing

Outsourcing Issues and Concerns Mission-critical IT systems Day-to-day company operations Company whose volume fluctuates widely

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Outsourcing

In considering Outsourcing Check ASP’s History Advantages of Outsourcing Potential Risks of Outsourcing

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Outsourcing

Offshore Outsourcing Firms send IT work overseas at increasing rate Gartner predicts that by 2005 (in U.S.) …

1 in 10 IT jobs at IT companies will move offshore 1 in 20 IT jobs at non-IT companies will move offshore

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In-House Software Development Options

Make/Buy (Build/Buy) Decision Most important consideration is total cost of

ownership (TCO) Commercial software packages

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Make or Buy Decision Companies that develop software for sale are

called software vendors Value-added reseller (VAR) Horizontal application Vertical application

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Developing Software In-House Satisfy unique business requirements Minimize changes in business procedures and

policies Meet constraints of existing systems Meet constraints of existing technology Develop internal resources and capabilities

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Purchasing a Software Package Lower costs Requires less time to implement Proven reliability and performance

benchmarks Requires less technical development staff Future upgrades provided by the vendor Input from other companies

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In-House Software DevelopmentOptions

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Customizing a Software Package – 3 Ways Purchase and have vendor(s) customize Negotiate directly with software vendor to make

changes Purchase and make your own modifications

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Creating User Applications A user application utilizes standard business

software User interface Help desk or information center (IC) Screen generators Report generators Read-only properties

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Role of the Systems Analyst

Evaluation and Selection team Primary objective

Eliminate system alternatives that will not work Rank system alternatives that will work Present viable alternatives to management for final

decision

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Analyzing Cost and Benefits

Financial Analysis Tools Payback Analysis Return on investment (ROI) Net present value (NPV)

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Analyzing Cost and Benefits

Cost-Benefit Analysis Checklist List each development strategy being considered Identify all costs and benefits for each alternative

Indicate when costs will be incurred and benefits realized Consider future growth and the need for scalability Include support costs for hardware and software Apply the financial analysis tools to each alternative Study the results and prepare a report to

management

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The Software Acquisition Process

Step 1: Evaluate the Information System Requirements

Prepare a request for proposal or quotation Request for proposal (RFP) Evaluation model Request for quotation (RFQ)

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Step 2: Identify Potential Vendors or Outsourcing Options

The Internet is a primary marketplace Another approach is to work with a consulting firm Another resource is the Internet bulletin board

system that contains thousands of forums, called newsgroups

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Step 3: Evaluate the Alternatives Existing users Application testing Benchmarking - benchmark Match each package against the RFP features and

rank the choices

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Step 4: Perform Cost-Benefit Analysis Identify and calculate TCO for each option you are

considering When you purchase software, what you are buying

is a software license If you purchase a software package, consider a

supplemental maintenance agreement

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Step 5: Prepare a Recommendation You should prepare a recommendation that

evaluates and describes the alternatives, together with the costs, benefits, advantages, and disadvantages of each option

At this point, you may be required to submit a formal system requirements document and deliver a presentation

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Step 6: Implement the Solution Implementation tasks will depend on the solution

selected Before the new software becomes operational, you

must complete all implementation steps, including loading, configuring, and testing the software; training users; and converting data files to the new system’s format

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Completion of Systems Analysis Tasks

System Requirements Document The system requirements document, or

software requirements specification, contains the requirements for the new system, describes the alternatives that were considered, and makes a specific recommendation to management

Like a contract Format and organize it so it is easy to read and

use

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Presentation to Management Begin your presentation with a brief overview of the

purpose and primary objectives of the system project, the objectives of this presentation, and what decisions need to made

Summarize the primary viable alternatives. For each alternative, describe the costs, advantages, and disadvantages

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Presentation to Management Explain why the evaluation and selection team

chose the recommended alternative Allow time for discussion and for questions and

answers Obtain a final decision from management or agree

on a timetable for the next step in the process

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Presentation to Management Based on their decision, your next task will be

one of the following• Implement an outsourcing alternative• Develop an in-house system• Purchase or customize a software package• Perform additional systems analysis work• Stop all further work

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The Transition to Systems Design

If management decides to develop the system in-house, then the transition to the systems design phase begins

Preparing for Systems Design Tasks It is essential to have an accurate and

understandable system requirements document

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The Transition to Systems Design

The Relationship between Logical and Physical Design

The logical design defines the functions and features of the system and the relationships among its components

The physical design of an information system is a plan for the actual implementation of the system

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Systems Design Guidelines

The systems analyst must understand the logical design of the system before beginning the physical design of any one component

Data design User interface Systems design specification

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Systems Design Objectives The goal of systems design is to build a system that

is effective, reliable, and maintainable

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System Design Objectives User Considerations Data Considerations

Data should be entered into the system where and when it occurs because delays cause data errors

Data should be verified when entered to catch errors immediately Automated methods of data entry should be used whenever

possible Access for data entry should be controlled and all entries or

changes to critical data values should be reported – audit trails

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System Design Objectives Data Considerations

Data should be entered into a system only once Data duplication should be avoided

Architecture considerations Use a modular design Design modules that perform a single function are

easier to understand, implement, and maintain

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Design Trade-Offs Design goals often conflict with each other Most design trade-off decisions that you will face

come down to the basic conflict of quality versus cost

Avoid decisions that achieve short-term savings but might mean higher costs later

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Prototyping

Prototyping produces an early, rapidly constructed working version of the proposed information system, called a prototype

Prototyping Methods System prototyping Design prototyping Throwaway prototyping

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Prototyping

Prototyping Methods Prototyping offers many benefits

Users and systems developers can avoid misunderstandings

Managers can evaluate a working model more effectively than a paper specification

Consider potential problems The rapid pace of development can create quality

problems In very complex systems, the prototype becomes

unwieldy and difficult to manage

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Prototyping

Prototyping Tools Systems analysts can use powerful tools to develop

prototypes CASE tools Application generators Report generators Screen generators Fourth-generation language (4GL) Fourth-generation environment

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Prototyping

Limitations of Prototypes A prototype is a functioning system, but it is less

efficient than a fully developed system Systems developers can upgrade the prototype into

the final information system by adding the necessary capability

Otherwise, the prototype is discarded Other Modeling Tools

Systems flowchart American National Standards Institute (ANSI)

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Chapter Summary

This chapter describes system development strategies, the preparation and presentation of the system requirements document, and the transition to the systems design phase of the SDLC

An important trend that views software as a service, rather than a product, has created new software acquisition options

Systems analysts must consider Web-based development environments

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Chapter Summary

The systems analyst’s role in the software development process depends on the specific development strategy

The most important factor in choosing a development strategy is total cost of ownership (TCO)

The process of acquiring software involves a series of steps

Any questions?

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Systems Analysis & Design (Sixth Edition) 1 Chapter 5 Development Strategies PHASE 2: SYSTEMS ANALYSIS