1 / 56

CHAPTER 9

CHAPTER 9. DEVELOPING IT SYSTEMS Bringing IT Systems to Life. 9-2. Introduction. Every Organization Is Using Information Technology. But IT systems don 抰 magically appear. Organizations spend billions of dollars every year developing systems.

avian
Download Presentation

CHAPTER 9

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. CHAPTER 9 DEVELOPING IT SYSTEMS Bringing IT Systems to Life

  2. 9-2 Introduction Every Organization Is Using Information Technology • But IT systems don抰 magically appear. • Organizations spend billions of dollars every year developing systems. • Organizations also spend billion of dollars buying systems that have already been developed. • The latest trend is to let knowledge workers take over much of the development process.

  3. 9-3 Introduction YOUR FOCUS IN THIS CHAPTER • The Who, How, and Why of Software Development • Insourcing and the Traditional SDLC • How to Develop Systems for Yourself Through Selfsourcing • Letting Other Organizations Develop Your Systems (Outsourcing) • CASE Tools and Joint Application Development

  4. 9-4 Systems Development SYSTEMS DEVELOPMENT IS A QUESTION-AND-ANSWER SESSION • What systems should we develop? • When should we develop those systems? • Who should develop systems? • How should we go about developing systems? • Why is my participation important during the systems development process? In this chapter, we focus on who,how, and why.

  5. 9-5 Systems Development WHY IS YOUR PARTICIPATION IMPORTANT? 1.You are a business process expert 2.You are a liaison to the customer 3.You are a quality control analyst 4.You are (or will be) a manager of other people

  6. 9-6 Systems Development WHO SHOULD DEVELOP SYSTEMS? • You have three choices. 1.Insourcing - IT specialists within your organization. 2.Selfsourcing - Knowledge workers such as yourself. 3.Outsourcing - Another organization.

  7. 9-7 Systems Development HOW SHOULD YOU GO ABOUT DEVELOPING SYSTEMS? • We will look at five choices. 1.Traditional systems development life cycle 2.Prototyping 3.Application software packages 4.Computer-aided software engineering 5.Joint application development

  8. 9-8 Insourcing & SDLC INSOURCING AND THE TRADITIONAL SYSTEMS DEVELOPMENT LIFE CYCLE • INSOURCING involves choosing IT specialists within your organization to develop the system. • TRADITIONAL SYSTEMS DEVELOPMENT LIFE CYCLE (TRADITIONAL SDLC) - a structured step-by-step approach to developing systems that creates a separation of duties among IT specialists and knowledge workers.

  9. 9-9 Insourcing & SDLC • Knowledge workers are the business process experts and the quality control analysts. • IT specialists are responsible for design, implementation, and support of the system. The 6 steps of the traditional SDLC: 1.Planning (Ch. 8) 4.Design 2.Scoping 5.Implementation 3.Analysis 6.Support See Figure 9.2, page 346

  10. 9-10 Insourcing & SDLC SCOPING - STEP #2 • Lay the foundation for the systems development process of a specific system. • Key Tasks During Scoping: • Determine which business units will be affected • Gather the project team • Review existing applications for needed interfaces • Perform an initial feasibility review • Develop a plan for proceeding

  11. 9-11 Insourcing & SDLC YOUR ROLE DURING SCOPING • Define the exact problem or opportunity • Participate in developing a plan for proceeding

  12. 9-12 Insourcing & SDLC ANALYSIS - STEP #3 • Determine the logical requirements for the proposed system. • The key in this step is logical, not physical. • Focus only on your information and processes from a logical point of view. • Key Tasks During Analysis: • Model, study, and analyze the current system • Define new information and processing requirements • Model the new system (logical only) • Update the project plan and scope

  13. 9-13 Insourcing & SDLC YOUR ROLE DURING ANALYSIS • Provide information concerning how the system currently works. • Provide information concerning new information and processing requirements. • Monitor and justify the new feasibility review.

  14. 收集用户需求的方法 • 询问用户 • 从现行系统获得 • 企业活动进行分析获得 • 原形法获得

  15. 数据流程图 • 处理 • 数据流 • 数据存储 • 外部实体

  16. 9-14 Insourcing & SDLC DESIGN - STEP #4 • Build a technical blueprint of how the proposed system will work. • IT specialists complete most of the tasks here. • Your role becomes that of quality assurance. • Key Tasks During Design: • Identify alternative technical solutions • Analyze alternative solutions and choose the best • Update the project plan and scope

  17. 9-15 Insourcing & SDLC YOUR ROLE DURING DESIGN • Assure that the recommended technical solution meets the logical requirements. • Monitor and justify the project plan.

  18. 9-16 Insourcing & SDLC IMPLEMENTATION - STEP #5 • Bring the proposed system to life and place it in the organization. • Key Tasks During Implementation: • Programming, testing, and training • Hardware acquisition and installation • Conversion: • PARALLEL - using the old and new simultaneously • PLUNGE - immediately using the new • PILOT - converting only a group of people first • PIECEMEAL - converting only a portion of the system first

  19. 9-17 Insourcing & SDLC YOUR ROLE DURING IMPLEMENTATION • Determine the best training method. • Determine the best conversion method. • Provide complete testing of the new system. • Monitor the budget and schedule and look for 搑unaway?projects.

  20. 9-18 Insourcing & SDLC SUPPORT - STEP #6 • Final sequential step of any systems development process. • Ensure that the system continues to meet stated goals. • You may need to make minor modifications or completely overhaul the system at some point.

  21. 9-19 Insourcing & SDLC KEY TASKS AND YOUR ROLE DURING SUPPORT • KEY TASKS: • React to changes in information and processing needs. • Assess the worth of the system in terms of the strategic plan of the organization. • YOUR ROLE: • Provide a mechanism for people to request changes. • Assess the worth of proposed changes before passing them to the IT specialists.

  22. 9-20 Insourcing & SDLC ADVANTAGES OF INSOURCING AND THE SDLC • Allows your organization to tailor a system to your exact needs. • Uses a structured step-by-step approach. • Creates a separation of duties between IT specialists and knowledge workers. • Requires key deliverables before proceeding to the next step.

  23. 9-21 Insourcing & SDLC DISADVANTAGES OF INSOURCING AND THE SDLC • It takes time to get exactly what you want. • Some smaller projects suffer from a structured approach. • IT specialists and knowledge workers speak different languages, creating communications gaps. • If you omit a requirement early, it can be costly to correct that mistake later.

  24. 9-22 Selfsourcing SELFSOURCING the development and support of IT systems by knowledge workers with little or no help from IT specialists. • Selfsourcing is an important part of knowledge worker computing in which you develop your own systems. • Selfsourcing is an option for who. • When selfsourcing, you almost always employ prototyping as a how.

  25. 9-23 Prototyping PROTOTYPING - BUILDING MODELS • PROTOTYPING is the process of building a model that demonstrates the features of a proposed product, service, or system. • A PROTOTYPE is a model of a proposed product, service, or system. • Most industries prototype all the time (think about the automobile industry). • Prototyping can also be a valuable tool in systems development.

  26. 9-24 Prototyping Prototyping Can Aid in... • Gathering requirements - because prototyping is iterative. • Helping determine requirements - especially if people don抰 know what they want. • Proving that a system is technically feasible - these prototypes are called PROOF-OF-CONCEPT PROTOTYPES. • Selling the idea of a proposed system - these prototypes are called SELLING PROTOTYPES.

  27. 9-25 Prototyping THE PROTOTYPING PROCESS 1.Identify Basic Requirements 2.Develop Initial Prototype 3.Knowledge Worker Reviewing 4.Revise and Enhance the Prototype Continue the iterative process between steps 3 and 4 until everyone is happy with the prototype. See Figure 9.7, page 361

  28. 9-26 Prototyping PROTOTYPING ADVANTAGES • Encourages active knowledge worker participation. • Helps resolve discrepancies among knowledge workers. • Gives knowledge workers a feel for the final system. • Helps determine technical feasibility. • Helps sell the idea of a proposed system.

  29. 9-27 Prototyping PROTOTYPING DISADVANTAGES • Leads people to believe the final system will follow shortly. • Gives no indication of performance under operational conditions. • Leads the project team to forgo proper testing and documentation.

  30. 9-28 Selfsourcing SELFSOURCING PROCESS STEPS 1. SCOPING • Define the goals of the new system • Create a project plan • Identify any systems that require an interface • Determine needed external support 2. ANALYSIS • Study and model current system • Understand interfaces in detail • Define and prioritize your requirements See Figure 9.8 and the box on page 363

  31. 9-29 Selfsourcing SELFSOURCING PROCESS STEPS 3. DESIGN • Select a design target • Acquire the necessary hardware and software • Develop an initial prototype 4. IMPLEMENTATION • Fully develop prototype into a complete system • Test the new system • Train • Convert to the new system • Completely document the new system 5. SUPPORT • Provide ongoing maintenance

  32. 9-30 Selfsourcing SELFSOURCING ADVANTAGES • Improves requirements determination. • Increases knowledge worker participation and sense of ownership. • Increases speed of systems development.

  33. 9-31 Selfsourcing SELFSOURCING PITFALLS • Inadequate knowledge worker expertise leads to inadequately developed systems. • Lack of organizational focus creates 損rivatized?IT systems. • Insufficient analysis of design alternatives leads to subpar IT systems. • Lack of documentation and external support lead to short-lived systems.

  34. 9-32 Outsourcing OUTSOURCING is the delegation of specific work to a third party for a specified length of time, at a specified cost, and at a specified level of service. • FORMS OF SYSTEMS DEVELOPMENT OUTSOURCING (See Figure 9.9, page 366): 1.Purchase existing application software package. 2.Purchase existing application software package and request modifications. 3.Outsource development of a system for which no application software package exists.

  35. 9-34 Outsourcing THE OUTSOURCING PROCESS • Select a Target System • Establish Logical Requirements • Develop a Request for Proposal (RFP) • Evaluate RFP Returns and Choose a Vendor • Test and Accept the Solution • Monitor and Reevaluate

  36. 9-33 Outsourcing REQUEST FOR PROPOSAL (RFP) • An RFP is a formal document that outlines your logical requirements of the proposed system and invites outsourcing organizations to submit bids for its development. • An RFP is the most important document in the outsourcing process. • It includes your logical system requirements, needed development time frame, how RFP returns will be scored and evaluated, and a host of other valuable information.

  37. RFP should includes: • Problem statement • Description of current system • Description of proposed system • Request for support plan • Request for development time frame • Request for statement of outsourcing costs • How RFP returns will be scored • Deadline for RFP returns

  38. 9-35 Outsourcing OUTSOURCING ADVANTAGESAllows your organization to... • Focus on Unique Core Competencies • Exploit the Intellect of Another Organization • Better Predict Future Costs • Acquire Leading-Edge Technology • Reduce Costs • Improve Performance Accountability

  39. 9-36 Outsourcing OUTSOURCING DISADVANTAGESYour organization may suffer because it... • Reduces Technical Know-How for Future Innovation • Reduces Degree of Control • Increases Vulnerability of Strategic Information • Increases Dependency on Other Organizations

  40. 9-37 Other Tools SOME OTHER TOOLS AND METHODS - MORE HOWS • Computer-Aided Software Engineering Tools - that are mostly used by IT specialists to automate the systems development process. • Joint Application Development Workshops - that bring together management, IT specialists, and knowledge workers to define system requirements as a group.

  41. 9-38 CASE Tools CASE TOOLS • COMPUTER-AIDED SOFTWARE ENGINEERING (CASE) TOOLS automate some or all steps in the SDLC. • CASE tools help (1) model and store specific system information and (2) convert information to a new form. • CATEGORIES OF CASE TOOLS: • INTEGRATED CASE TOOLS for the entire SDLC. • UPPER CASE TOOLS for planning, scoping, analysis, and design. • LOWER CASE TOOLS for design, implementation, and support.

  42. 9-39 CASE Tools KEY FEATURES OF CASE TOOLS • PROJECT REPOSITORY - a database that contains information pertaining to all the systems development projects that your organization has undertaken using the CASE tool. • REVERSE ENGINEERING - the ability of a CASE tool to analyze existing software and create design documents from it.

  43. Step1:Planning • CASE tools help you model information concerning the goals and objectives of your organization, the current IT infrastructure, the IT systems plan, the structure of your organization, and current information and processes within your organization

  44. Step2:Scoping • CASE tools help you capture and work with any information relating to the groundwork for the development of a specific system, including the problem statement, goals of the new system, required interfaces, the feasibility review, project team members, and the project plan.

  45. Step3:Analysis • CASE tools help you model and capture the logical requirements for a proposed system and any new information and processes that must be present.

  46. Step4:Design • CASE tools help you model and capture technical alternatives for the proposed solution and generate detailed specifications concerning how the software should work.

  47. Step5:Implementation • CASE tools help you generate software automatically from detailed design.

  48. Step6:Support • Regenerate software after changing design specifications • Reverse-Engineer old systems to support changes

  49. 9-40 CASE Tools ADVANTAGES OF CASE TOOLS • Increased speed and efficiency of SDLC. • Repository of project information. • Valuable control checking. • Deployment of systems across multiple platforms.

More Related