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E. Wainright Martin Carol V. Brown Daniel W. DeHayes Jeffrey A. Hoffer William C. Perkins MANAGINGINFORMATIONTECHNOLOGY FIFTH EDITION CHAPTER 10 M ETHODOLOGIES.

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Presentation on theme: "E. Wainright Martin Carol V. Brown Daniel W. DeHayes Jeffrey A. Hoffer William C. Perkins MANAGINGINFORMATIONTECHNOLOGY FIFTH EDITION CHAPTER 10 M ETHODOLOGIES."— Presentation transcript:

1 E. Wainright Martin Carol V. Brown Daniel W. DeHayes Jeffrey A. Hoffer William C. Perkins MANAGINGINFORMATIONTECHNOLOGY FIFTH EDITION CHAPTER 10 M ETHODOLOGIES FOR C USTOM S OFTWARE D EVELOPMENT

2 © 2005 Pearson Prentice-Hall Chapter S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 385 Systems development life cycle (SDLC) – a highly structured approach for development of new customized software applications

3 © 2005 Pearson Prentice-Hall Chapter S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 386 The SDLC Steps Figure 10.1 The Systems Development Life Cycle Key characteristic is extensive formal reviews required at end of each major step

4 © 2005 Pearson Prentice-Hall Chapter S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 386 The SDLC Steps Figure 10.2 Cost Breakdown for $1 Million SDLC Project Hallmark of SDLC approach: extensive up-front time spent determining requirements to avoid expensive changes later

5 © 2005 Pearson Prentice-Hall Chapter S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 386 The SDLC Steps SDLC:   Most often requires a lot of documentation   Outputs from one step inputs to next   Often referred to as the “waterfall” model

6 © 2005 Pearson Prentice-Hall Chapter

7 © 2005 Pearson Prentice-Hall Chapter S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 388 Definition Phase – Requirements Definition Focuses on logical design: processes, data flows, and data interrelationships – not specific physical implementation Deliverable – system requirements document:   Detailed descriptions of inputs and outputs, processes used to convert input data to outputs   Formal diagrams and output layouts   Revised cost/benefit analysis   Revised plan for remainder of project

8 © 2005 Pearson Prentice-Hall Chapter S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 389 Construction Phase System Design System Building System Testing Figure 10.3 Characteristics of High Quality Systems Documentation is a major mechanism of communication during development process

9 © 2005 Pearson Prentice-Hall Chapter S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 390 Implementation Phase Installation Operations Maintenance

10 © 2005 Pearson Prentice-Hall Chapter Page 391 Implementation Phase – Installation Figure 10.4 Implementation Strategies Parallel Strategy

11 © 2005 Pearson Prentice-Hall Chapter Page 392 Implementation Phase – Maintenance Figure 10.5 Percent of Development Resources Devoted to Maintenance

12 © 2005 Pearson Prentice-Hall Chapter Page 392 Implementation Phase – Maintenance Figure 10.6 The Widening Gap Between Organization’s Needs and System’s Performance

13 © 2005 Pearson Prentice-Hall Chapter S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 393 The SDLC Project Team Usually temporary Includes personnel from IS and business units Has a project manager   Traditionally from IS   Can be from business unit   May be one from each   Responsible for success of project – delivering quality system on time and within budget

14 © 2005 Pearson Prentice-Hall Chapter S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 394 The SDLC Project Team Includes systems analysts   Have critical roles   Work closely with business managers and end users   Have problem-solving skills, knowledge of IT capabilities, strong business understanding Has a business sponsor and a champion

15 © 2005 Pearson Prentice-Hall Chapter S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 394 Managing an SDLC Project Characteristics critical for success:   Manageable project size   Accurate requirements definition   Executive sponsorship

16 © 2005 Pearson Prentice-Hall Chapter S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 395 Figure 10.7 Costs of Error Correction by SDLC Step Managing an SDLC Project (Adapted from Boehm, 1976)

17 © 2005 Pearson Prentice-Hall Chapter S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 395 SDLC Advantages and Disadvantages Figure 10.8 Advantages and Disadvantages of Traditional SDLC Approach

18 © 2005 Pearson Prentice-Hall Chapter P ROTOTYPING M ETHODOLOGY Page 396 Prototyping approach:   Takes advantage of availability of fourth generation procedural languages and relational database management systems   Enables creation of system (or part of system) more quickly, then revise after users have tried it   Is a type of evolutionary development process

19 © 2005 Pearson Prentice-Hall Chapter P ROTOTYPING M ETHODOLOGY Page 396 Prototyping examples:   Input and output screens developed for users to test as part of requirements definition   “First-of-a-series” – a completely operational prototype used as a pilot   “Selected features” – only some essential features included in prototype, more added later   Prototyping used as a complete alternative to traditional SDLC methodology

20 © 2005 Pearson Prentice-Hall Chapter P ROTOTYPING M ETHODOLOGY Page 396 Prototyping used as a complete alternative to traditional SDLC methodology:   Good when requirements hard to define   Good when system needed quickly   Impractical for large, complex applications

21 © 2005 Pearson Prentice-Hall Chapter Page 397 The Prototyping Steps Figure 10.9 The Prototyping Life Cycle

22 © 2005 Pearson Prentice-Hall Chapter P ROTOTYPING M ETHODOLOGY Page 398 Representatives from IS and user management necessary Need team members who can quickly build systems using advanced tools Requires dedicated business user roles The Prototyping Project Team

23 © 2005 Pearson Prentice-Hall Chapter P ROTOTYPING M ETHODOLOGY Page Advantages:   Only basic requirements needed at front end   Used to develop systems that radically change how work is done, so users can evaluate   Allows firms to explore use of new technology   Working system available for testing more quickly   Less strong top-down commitment needed at front end   Costs and benefits can be derived after experience with initial prototype   Initial user acceptance likely higher Prototyping Advantages and Disadvantages

24 © 2005 Pearson Prentice-Hall Chapter P ROTOTYPING M ETHODOLOGY Page 399 Disadvantages:   End prototype often lacks security and control features   May not undergo as rigorous testing   Final documentation may be less complete   More difficult to manage user expectations Prototyping Advantages and Disadvantages

25 © 2005 Pearson Prentice-Hall Chapter P ROTOTYPING M ETHODOLOGY Page 399 Prototyping within an SDLC Process Figure SDLC with Prototyping to Define Requirements

26 © 2005 Pearson Prentice-Hall Chapter P ROTOTYPING M ETHODOLOGY Page 399 Prototyping within an SDLC Process Figure Prototyping/Piloting Replaces SDLC Definition Phase

27 © 2005 Pearson Prentice-Hall Chapter N EWER A PPROACHES Page 400 Rapid Application Development (RAD) Figure Four-Step RAD Cycle Hybrid methodology – aspects of SDLC and prototyping Goal is to produce a system in less than a year

28 © 2005 Pearson Prentice-Hall Chapter N EWER A PPROACHES Page Rapid Application Development (RAD) Joint application design (JAD) – a technique in which a team of users and IS specialists engage in an intense and structured process in order to minimize the total time required for gathering information from multiple participants

29 © 2005 Pearson Prentice-Hall Chapter N EWER A PPROACHES Page Rapid Application Development (RAD) Joint application design (JAD) – a technique in which a team of users and IS specialists engage in an intense and structured process in order to minimize the total time required for gathering information from multiple participants Computer-aided software engineering (CASE) – any software tool used to automate one or more steps of a software development methodology

30 © 2005 Pearson Prentice-Hall Chapter N EWER A PPROACHES Page 401 Rapid Application Development (RAD) Figure Types of CASE Tools (Adapted from Valacich, George, and Hoffer, 2001)

31 © 2005 Pearson Prentice-Hall Chapter N EWER A PPROACHES Page 402 Rapid Application Development (RAD) Figure RAD Advantages and Disadvantages

32 © 2005 Pearson Prentice-Hall Chapter N EWER A PPROACHES Page 402 Agile Software Development Discipline Alternative methodology for smaller projects Based on four key values:   Simplicity   Communication   Feedback   Courage One type: Extreme Programming (XP)   Programmers write code in pairs   Use simple design and frequent testing

33 © 2005 Pearson Prentice-Hall Chapter M ANAGING S OFTWARE P ROJECTS U SING O UTSOURCED S TAFF Page 402 Advantages:   Helps keep software development costs down   Uses technical expertise not available in-house   Can often complete projects more quickly Off-site outsourcing:   Onshore – within same country or region   Offshore – not within same country or region

34 © 2005 Pearson Prentice-Hall Chapter M ANAGING S OFTWARE P ROJECTS U SING O UTSOURCED S TAFF Page 402 Offshore alternative good option when:   System requirements well-defined and remain stable   Time is of essence and 7x24 hour availability of resources a good idea   Cost of project important

35 © 2005 Pearson Prentice-Hall Chapter M ANAGING S OFTWARE P ROJECTS U SING O UTSOURCED S TAFF Page Guidelines for managing offsite outsourcer:   Manage expectations, not staff   Take explicit actions to integrate the offsite workers   Communicate frequently   Abandoning informal ways may result in increased rigor


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