SYSTEMS ANALYSIS DESIGN

1. PHASE 2 SYSTEMS ANALYSIS Evaluating Alternatives and Strategies SYSTEMS ANALYSIS & DESIGN

2. Chapter 5 Evaluating Alternatives and Strategies

3. Objectives Evaluate various alternatives when planning systems development and acquisition Explain the advantages and disadvantages of in-house development versus purchasing a software package List the steps in purchasing and evaluating a software package

4. Objectives Explain the differences between a request for proposal (RFP) and a request for quotation (RFQ) Describe the contents of the system requirements document and explain its purpose Explain the prototyping process and describe a typical situation where prototyping is used

5. Objectives Describe computer-aided software engineering (CASE) tools and explain how they are used during the systems development life cycle Explain how systems flowcharts and state-transition diagrams are used

6. Chapter 5 covers the remaining tasks in the systems analysis phase Evaluation of alternative solutions Preparation of the system requirements document Presentation to management Introduction

7. Evaluating Software Alternatives Make or buy decision In-house software Developed by the company’s IS department Software package Purchased or leased from software publishers or vendors Horizontal application Vertical application

8. Evaluating Software Alternatives Developing software in-house Reasons for in-house development Satisfy unique requirements Minimize changes in business procedures and policies Meet constraints of existing systems Meet constraints of existing technology Develop internal resources and capabilities

9. Evaluating Software Alternatives Buying a software package Reasons for buying a software package Lower costs Requires less time to implement Proven reliability and performance benchmarks Implemented by other companies Requires less technical development staff Future upgrades provided by the vendor

10. Evaluating Software Alternatives Customizing software packages Purchase a basic package that can be customized to suit your needs Negotiate with software vendor to make enhancements to suit your needs Purchase the package and make your own modifications

11. Evaluating Software Alternatives Other software alternatives Outsourcing End-user systems Enterprise computing

12. Evaluating Software Alternatives Outsourcing Using outside companies to handle part of the workload, on short-term or long-term basis Contract personnel firms Systems management or facilities management firms

13. Evaluating Software Alternatives End-user systems Major factor in systems planning and development Applications can be managed by end-users

14. Evaluating Software Alternatives End-user systems Major factor in systems planning and development Applications can be managed by end-users Software suites offer integrated applications Interactive Help features include wizards Security concerns might require read-only files Information centers (IC) can support end-user systems

15. Evaluating Software Alternatives Enterprise computing Overall information management strategy Key is effective integration of information resources Many systems involve client/server architecture

16. Evaluating Software Alternatives Selecting a software alternative Decision will affect remaining SDLC phases Systems analyst’s involvement depends on which alternative is selected

17. Steps in Evaluating and Purchasing Software Packages Five step process 1. Evaluate the information system requirements 2. Identify potential software vendors 3. Evaluate software package alternatives 4. Make the purchase 5. Install the software package

18. Steps in Evaluating and Purchasing Software Packages Step 1: evaluate the information system requirements Identify the key features of the system Estimate volume and future growth Specify any hardware constraints Prepare a request for proposal or quotation

19. Steps in Evaluating and Purchasing Software Packages Step 2: identify potential software vendors Next step is to contact potential vendors An RFP will help vendors to identify solutions Various sources of information on suppliers Retailers Computer manufacturers Industry trade journals Systems consultants

20. Steps in Evaluating and Purchasing Software Packages Step 3: evaluate software package alternatives Object is to compare software packages and select the best alternative Obtain information from many sources Vendor presentations and literature

21. Steps in Evaluating and Purchasing Software Packages Step 3: evaluate software package alternatives Object is to compare software packages and select the best alternative Obtain information from many sources Vendor presentations and literature Product documentation Trade publications Companies that perform software testing/evaluation

22. Steps in Evaluating and Purchasing Software Packages Step 3: evaluate software package alternatives Object is to compare software packages and select the best alternative Obtain information from many sources Vendor presentations and literature Product documentation Trade publications Companies that perform software testing/evaluation Contact users of the package Benchmark test

23. Steps in Evaluating and Purchasing Software Packages Step 4: make the purchase Software licenses Lease agreements Maintenance agreements

24. Steps in Evaluating and Purchasing Software Packages Step 5: install the software package Installation time depends on size and complexity Before using the package, complete all implementation steps Loading, configuring, and testing the software Training users Converting data files to new format

25. Hardware Alternatives Hardware decisions use the same five-step approach as software decisions Evaluate system requirements Identify potential hardware vendors Evaluate hardware alternatives Make the purchase Install the hardware

26. Hardware Alternatives Other issues to consider Turnkey systems Site preparation New workstations Network cabling Raised floors Conditioned electrical lines Fire extinguishing equipment Uninterruptible power supplies (UPSs)

27. TRADEOFF How do you select the best alternative? Most companies combine In-house developed software Software packages Outsourcing End-user systems Object is to develop a list of viable alternatives All viable alternatives must be evaluated Feedback from users is essential

28. A KEY QUESTION How will you prepare for the meeting with Doug Sawyer? What is your strategy and how will you present your alternatives? Consider the pros and cons of in-house development vs. purchase of a package

29. Completion of Systems Analysis System requirements document Also called software requirements specification Describes alternatives and makes recommendation to management Similar to a contract for what will be delivered Must be clear and understandable to users

30. Completion of Systems Analysis Presentation to management Five probable management decisions 1. Develop an in-house system 2. Modify the current system 3. Purchase or customize a software package 4. Perform additional systems analysis work 5. Stop all further work

31. Completion of Systems Analysis Presentation guidelines and suggestions Give overview of the project’s purpose and objectives Summarize alternatives, with costs, pros, and cons Explain why the recommended alternative was chosen Allow time for discussion, questions, and answers Obtain final decision from management or timetable for next step

32. Prototyping A prototype is an early, rapidly constructed working version of the system A working model helps users understand the system Prototyping produces a less-expensive model Can eliminate problems before the final version

33. Prototyping Prototyping software tools Nonprocedural tools specify the problem to be solved, rather than how to solve it Fourth-generation environment prototyping tools CASE toolkit

34. Prototyping Prototyping software tools Nonprocedural tools specify the problem to be solved, rather than how to solve it Fourth-generation environment prototyping tools CASE toolkit Report writer or report generator

35. Prototyping Fourth-generation environment prototyping tools CASE toolkit Report writer or report generator Query language Screen generator, screen painter, screen mapper, or form generator Program generator or code generator Fourth-generation language (4GL)

36. Prototyping Prototyping during systems analysis Goal is to develop a working model quickly Early way to test essential system features Prototype can be upgraded or replaced during later SDLC phases

37. Computer-Aided SoftwareEngineering (CASE) CASE tools increase productivity Full set of CASE tools is called a toolkit CASE tools can handle variety of tasks Create and integrate data flow diagrams Logical and physical design Generation of program code CASE tool example is Visible Analyst

38. Computer-Aided SoftwareEngineering (CASE) Categories of CASE tools Diagramming tools

39. Computer-Aided SoftwareEngineering (CASE) Categories of CASE tools Diagramming tools Prototyping tools Central repository

40. Computer-Aided SoftwareEngineering (CASE) Categories of CASE tools Diagramming tools Prototyping tools Central repository Data design tools Project management tools Maintenance tools Another CASE example: Hyper Analysis Toolkit (HAT)

41. Computer-Aided SoftwareEngineering (CASE) Using CASE tools Data design tool Programming tool Program debugger Code generator Project management tool Maintenance tool

42. Computer-Aided SoftwareEngineering (CASE) Categories of tools Forward engineering tools (used during SDLC work) Reverse engineering tools (convert program code into design specifications) Reengineering toolkit (uses reverse and forward engineering) Front-end, or upper-CASE tools (used in first three SDLC phases) Back-end, or lower-CASE tools (used during systems implementation and operation phases)

43. TRADEOFF Pros and cons of CASE tools Advantages Automate manual tasks Encourage standard methods Improve accuracy and overall quality of end product

44. TRADEOFF Disadvantages Cost of CASE software and hardware needed Lack of CASE standards Other issues CASE does not replace need for analyst’s skills Initial preparation effort not always worthwhile

45. A KEY QUESTION Does the new CASE toolkit at Sunnyside Beverages replace the need to teach new analysts how to create DFDs? How would you respond?

46. Alternative Graphical Tools Other tools can be used in addition to DFDs Systems flowcharts State-transition diagrams

47. Alternative Graphical Tools Systems flowcharts Display major process, input, and output operations Primarily used in physical modeling Various symbols represent data or files in specific physical media Shape of symbol indicates the purpose Lines with arrowheads indicate the flow of data

48. Alternative Graphical Tools State-transition diagrams Show time sequence of real-time systems A real-time system processes data and feeds it back to the system Real-time system examples Automobile cruise control systems Microprocessor-controlled thermostats Microwave oven control system

49. Transition to Systems Design Next SDLC phase is system design for in-house system development Size of the development team depends on the company and the nature of the project System requirements document An accurate and understandable document is essential Document contains design for the new system Must reflect thorough analysis and effective communication

50. SOFTWEAR, LIMITED Rick and Carla attend training workshop for SWL’s new CASE toolkit: Visible Analyst The development team evaluates various alternatives and potential solutions The IS department recommendations: 1. Purchase a commercial package for payroll functions from Pacific Software Solutions 2. Develop an ESIP system in-house to meet SWL’s unique requirements

51. SOFTWEAR, LIMITED Other tasks accomplished by Rick and Carla Completed the logical model, alternative evaluations, and cost/time estimates Prepared the system requirements document Printed and distributed the document Scheduled a presentation to management Prepared and rehearsed the presentation Developed visual aids Tried to anticipate questions

52. SOFTWEAR, LIMITED Results of the presentation Recommendation was approved Top managers indicated support for the project The next step Negotiate a contract with Pacific Software Solutions for purchase of the payroll package Begin systems design work for the ESIP system