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Systems Development MIS 503 Management Information Systems MBA Program.

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Presentation on theme: "Systems Development MIS 503 Management Information Systems MBA Program."— Presentation transcript:

1 Systems Development MIS 503 Management Information Systems MBA Program

2 SYSTEMS DEVELOPMENT LIFE CYCLE METHODOLOGY Page 385 Systems development life cycle (SDLC) – a highly structured approach for development of new customized software applications

3 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

4 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

5 Managing Change The ability to manage change is critical to the success of systems development. –The new or modified systems created during systems development will inevitably cause change. –Managing change requires the ability to recognize existing or potential problems.

6 There is nothing more difficult to plan, more doubtful of success, nor more dangerous to manage than the creation of a new information system. For the initiator has the enmity of all who would profit from the preservation of the old system and merely luke warm defenders in those who would gain from the new one. Significant Quote

7 Establishing Objectives for Systems Development Systems development objectives should be supportive of, and aligned with, organizational goals. There are four kinds of objectives that should be considered: –Performance objectives. –Cost objectives. –Control objectives. –Complexity objectives.

8 Systems Development Methodologies A key factor in completing a successful systems development project is to adopt a methodology. A methodology is a way of doing things.

9 A systems development methodology is an assortment of rules and standards that govern the approach taken to all tasks associated with systems development. In structured systems development the systems development tasks are broken down into small, easily managed parts. Systems Development Methodologies

10 Top-down design means the entire system can be viewed as a layered set of descriptions, each of which could be decomposed, or “peeled back,” to reveal more detailed specifications for smaller parts of the system. Systems Development Methodologies

11 Structured Walkthrough A structured walkthrough is a planned and pre-announced review of the progress of a particular project deliverable--a specific project outcome, a structure chart, or a human procedure. The walkthrough helps team members review and evaluate the program of components of a structured project.

12 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

13 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

14 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

15 S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 387-388 Definition Phase – Feasibility Analysis Types of feasibility – economic, operational, and technical Deliverable – 10-20 page document: –Executive overview and recommendations –Description of what system would do and how it would operate –Analysis of costs and benefits –Development plan

16 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

17 Brook’s Law: Adding manpower to a late software project makes it later! (Frederick P Brooks Jr.) Significant Quote Hofstadter's Law: It always takes longer than you think, even when you take Hofstadter's Law into account. (Douglas Hofstadter)

18 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

19 S YSTEMS D EVELOPMENT L IFE C YCLE M ETHODOLOGY Page 390 Implementation Phase Installation Operations Maintenance

20 Page 391 Implementation Phase – Installation Figure 10.4 Implementation Strategies Parallel Strategy

21 Page 392 Implementation Phase – Maintenance Figure 10.5 Percent of Development Resources Devoted to Maintenance

22 Page 392 Implementation Phase – Maintenance Figure 10.6 The Widening Gap Between Organization’s Needs and System’s Performance

23 Bove’s Theorem: The remaining work to finish in order to reach your goal increases as the deadline approaches. Significant Quote Walking on water and developing software from a specification are easy if both are frozen. (Edward V Berard)

24 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

25 Deadline Dan’s Demon: Every task takes twice as long as you think it will take. If you double the time you think it will take, it will actually take four times as long. Meskimens Law There is never time to do it right, but there is always time to do it over Significant Quote

26 User Acceptance User acceptance document - a formal agreement signed by the user that a phase of the installation or the complete system is approved. This is a legal document that usually removes or reduces the IS vendor from liability or responsibility for problems that occur after it is signed.

27 Causes of Maintenance Some major causes of program maintenance are: –New requests from stakeholders, users, and managers. –Bugs or errors in the program. –Technical and hardware problems. –Corporate mergers and acquisitions. –Governmental regulations.

28 Significant Quote Nixons Law The man who can smile when things go wrong has thought of someone to blame. Flon's axiom There does not now, nor will there ever, exist a programming language in which it is the least bit hard to write bad programs. (Lawrence Flon)

29 Trends in Systems Development

30 Operational and Rapid Prototyping An operational prototype is a prototype that works. A partially operational prototype has some components that are operational. A rapid prototype allows system stakeholders and users to see a mockup of the subsystem much faster, which enables earlier changes.

31 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 PROTOTYPING METHODOLOGY

32 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 PROTOTYPING METHODOLOGY

33 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 PROTOTYPING METHODOLOGY

34 Page 397 The Prototyping Steps Figure 10.9 The Prototyping Life Cycle

35 Page 398-399 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 PROTOTYPING METHODOLOGY

36 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 PROTOTYPING METHODOLOGY

37 Page 399 Prototyping within an SDLC Process Figure 10.10 SDLC with Prototyping to Define Requirements

38 P ROTOTYPING M ETHODOLOGY Page 399 Prototyping within an SDLC Process Figure 10.11 Prototyping/Piloting Replaces SDLC Definition Phase

39 N EWER A PPROACHES Page 400 Rapid Application Development (RAD) Figure 10.12 Four-Step RAD Cycle Hybrid methodology – aspects of SDLC and prototyping Goal is to produce a system in less than a year

40 N EWER A PPROACHES Page 400-401 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

41 N EWER A PPROACHES Page 400-401 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

42 N EWER A PPROACHES Page 401 Rapid Application Development (RAD) Figure 10.13 Types of CASE Tools (Adapted from Valacich, George, and Hoffer, 2001)

43 N EWER A PPROACHES Page 402 Rapid Application Development (RAD) Figure 10.14 RAD Advantages and Disadvantages

44 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

45 T HE M AKE-OR- B UY D ECISION Page 406 Decision should be made jointly by business managers and IS professionals Advantages of purchasing: –Cost savings –Faster speed of implementation Disadvantages of purchasing: –Seldom exactly fits a company’s needs –Often forces trade-offs

46 P URCHASING M ETHODOLOGY Page 407 The Purchasing Steps Figure 11.1 The Purchasing Process

47 Page 407 Initiating the Purchasing Process Figure 11.2 Comparison of Costs and Building vs. Purchasing a System PURCHASING METHODOLOGY

48 Page 408 Establish Criteria for Selection Figure 11.3 Key Criteria for Software Package Selection PURCHASING METHODOLOGY

49 Page 409 Develop and Distribute the RFP Request for proposal (RFP) – a formal document sent to potential vendors inviting them to submit a proposal describing their software package and how it would meet the company’s needs PURCHASING METHODOLOGY

50 Page 410-411 Evaluation steps: –Review vendors’ responses from RFPs –Request demonstrations of leading packages –Request references from users of software packages in other companies –Assess how well package capabilities satisfy company’s needs –Understand extent of any additional development efforts or costs to tailor software –Make decision Evaluate Vendor Responses to RFP and Choose Package PURCHASING METHODOLOGY

51 Page 411 Evaluate Vendor Responses to RFP and Choose Package Figure 11.6 Matching Company Needs with Capabilities of the Package PURCHASING METHODOLOGY

52 Page 413 If no software package modifications required: –Skip system design and building steps –Move directly to system testing –Develop any necessary process changes If software package is modified: –Consider contracting with vendor or a third party for changes versus modifying in-house –Determine if changes are required to other existing company systems Construction Phase PURCHASING METHODOLOGY

53 Page 414-415 –Business managers and users –IS professionals –Project manager – usually a business manager –Software vendor personnel –Sometimes includes a third-party implementation partner –Purchasing specialists –Attorneys Project Team for Purchasing Packages PURCHASING METHODOLOGY

54 Page 416 Purchasing Advantages and Disadvantages Figure 11.7 Advantages and Disadvantages of Purchasing Packaged Software PURCHASING METHODOLOGY

55 Page 418 N EW P URCHASING O PTION: A PPLICATION S ERVICE P ROVIDERS (ASPs) New trend beginning 2000s Purchasing option: purchaser elects to use a “hosted” application rather than to purchase the software application and host it on its own equipment ASP is an ongoing service provider Company pays third party (ASP) for delivering the software functionality over the Internet to company employees and sometimes business partners

56 Page 418-419 N EW P URCHASING O PTION: A PPLICATION S ERVICE P ROVIDERS (ASPs) Some advantages: –Cost savings and faster speed of implementation –Usually involves monthly fees rather than large infrastructure investment Disadvantages: –Dependence on an external vendor for both software and ongoing operations –Good assessment of required service levels even more critical

57 End-User Systems Development End-user systems development is a term that was originally used to describe the development of information systems by individuals outside of the formal IS planning and departmental structure.

58 Potential Problems for Systems Development Solving the wrong problem. Poor problem definition and analysis. Poor communication. A project that is too ambitious. A lack of top management support. A lack of management and user involvement.

59 Failure to use a standard systems development approach. Inadequate or improper systems design. Poor testing and implementation. A lack of concern for maintenance. Potential Problems for Systems Development

60 Success Factors in Systems Development Clearly defined organizational goals. A sharp focus on, and clear understanding of, the most important business problems or opportunities. Clearly defined systems development objectives. Support of top-level managers. Involvement of users at all stages. Use of a proven systems development method. Creating or aligning incremental systems benefits with normal user work activities so as to provide incentives for effective system interaction. Managing change. A simple and straightforward design. Good training programs for all involved.

61 Global Sourcing The process of deciding where in the world a firm’s activities will be performed and who will perform the activities. –Fundamentally any activities that does not require direct customer contact, extensive local knowledge, or complex interactions can be sourced anywhere

62 Global Resourcing

63 Outshoring and Outsourcing

64 Definition of Outsourcing IS outsourcing is the commissioning of part or all of the IS activities an organization needs, and/or transferring the associated human and other IS resources, to one or more external IS suppliers IS Offshoring is the commissioning of part or all of the IS activities an organization needs to one or more other countries IS Insourcing is the sourcing of a business function within the firm (e.g., Kingland Systems)

65 IS Outsourcing Four Types of Outsourcing Relationships: q Support q Reliance q Alignment q Alliance

66 Outsourcing Grid Reliance Alliance SupportAlignment Strategic Impact of IS Applications Extent of Substitution by Vendors High Low

67 Outsourcing Decision Variables Relationships Division Among Suppliers and Contracts Management Structure Operational Structure Internal Organization of Outsourcing Coordination

68 Horizontal and Vertical Integration Diversification - increasing the number of products and services Differentiation - aka ‘disintegration’ - decreasing the number of subsequent phases in the production chain Specialization - reducing the number of products and services Integration - performing a larger number of phases in the production chain

69 Backward Vertical Disintegration Car manufacturer purchasing pre- assembled engines instead of purchasing and assembling the component parts themselves Decreasing the number of phases a firm performs by commissioning another entity within the production chain to perform those functions


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