4/8: Systems Analysis & Development

1. 4/8: Systems Analysis & Development • Systems change affecting organizations • Systems development • Influences on & challenges to implementation • Systems development approaches • Systems building methodologies

2. Systems development & org. change paradigm shift RISK reengineering rationalization automation RETURN

3. Systems development & org. change • Automation • Using the computer to speed up the performance of existing tasks automation RETURN

4. Systems development & org. change • Rationalization • Involves streamlining of standard operating procedures, eliminating obvious bottlenecks, so that automation makes operating procedures more efficient. rationalization

5. Systems development & org. change • Reengineering • Radical redesign of business processes, combining & eliminating steps to reduce waste and repetition, to improve cost, quality, and service. • Management must understand & measure current design to assess improvements with new design. reengineering

6. Systems development & org. change • Paradigm shift • Rethinking the nature of the business and the nature of the organization itself. paradigm shift

7. 2 Ways to Find the IS Requirements • Enterprise Analysis: “looking at the whole” • Central approach: ask large number of managers: • How they use information, where they get it • What their environments are like • What their objectives are • How they make decisions • What their data needs are • Create logical application groups: • Groups of data elements that support related sets of organizational processes. • Tends to automate whatever exists, no fundamental change.

8. 2 Ways to Find the IS Requirements • Strategic Analysis, or CSF: Critical Success Factors • CSFs shaped by industry, environment, and manager • Central approach: 3-4 personal interviews with top management, identify goals and the CSFs. • Advantages • smaller data set to analyze. • Takes into account the environment & industry. • Disadvantages: • it’s an art form • opinions may differ on what the CSFs are • Biased toward top management

9. Systems Development • All activities that produce an IS solution to an organizational problem or opportunity. • A structured kind of problem-solving with six distinct activities: • Systems analysis • Systems design • Programming • Testing • Conversion • Production & Maintenance

10. Systems Analysis • Defining the problem • Identifying its causes • Specifying the solution • Identifying the information requirements needed.

11. Systems Analysis • Includes a feasibility study • Technical feasibility • Is the proposed solution technically achievable? Is it possible? • Economic feasibility • Do the benefits outweigh the costs? • Operational feasibility • Will it work in the organizational & managerial framework? • Do an organizational impact analysis: • How a new IS will affect org. structure, attitudes, decision-making, and operations.

12. Systems Analysis: Info Requirements • Basically: who needs what information, when, where, and how? • Incredibly important!

13. Systems Design • Detailed how a systems will met the information requirements as determined by the systems analysis. • Like a blueprint of a house • Logical design • Lays out IS components and their relationships as they would appear TO USERS. • Shows what the proposed IS is supposed to DO. • Physical design • Specs out the hardware, sofware, databases, etc.

14. Programming & Testing • Programming: System specifications created in the design phase are translated into program code. • Testing: vital step, often shortchanged. • Unit testing: seeking errors in particular programs • System testing: does the whole thing work together? • Acceptance testing: evaluation by real users, review by management.

15. Conversion • Putting the new IS into production • Parallel strategy: • run both old & new simultaneously. • Direct cutover: • Old completely replaced by new on spec. day. • Pilot study: • Limited implementation by small group of users. • Phased approach: • Parts of new IS are introduced separately.

16. Production & Maintenance • New IS is up and running: in production. • At this point, changes in the IS are called “maintenance”. • Changes made are usually to improve efficiency.

17. Influences on & Challenges to Systems Implementation • User involvement & influence • Management support • Level of complexity & risk • Management of implementation

18. Systems Development Approaches • Traditional systems lifecycle • Prototyping • Application software packages • End-user development • Outsourcing

19. Traditional Systems Lifecycle • Variation of systems development cycle • Oldest method for building ISes, necessary for large, complex projects. • Steps: • Project definition • systems study • Design • Programming • Installation • Postimplementation

20. Other Approaches: Prototyping • Create an experimental system rapidly and inexpensively for end-users • Steps: • Identify the user’s basic requirements. • Develop an initial prototype. • Use the prototype. • Revise & enhance the prototype. • Iterative approach: repeat the process. • Especially good for end-user interfaces.

21. Other Approaches: Application Software Packages • Buying a premade, prepackaged application software package. • Prewritten code can often fulfill most requirements of an proposed IS. • Customization • Can be modified to meet needs better with optional add-ons.

22. Application Software Packages: Examples Accounts receivable; Bond & stock management; Computer-aided design (CAD) ; document imaging; E- mail; EnterpriseResource Planning (ERP); Groupware; Health care; HotelManagement; Internet telephone; Inventory control; Job costing; Library systems; Life insurance; Mailing labels; Mathematical / statistical modeling; Order processing; Payroll; Process control;Tax accounting; Web browser; Word processing

23. Other Approaches: End-User Development • End-users develop information system with little help from technical specialists using 4th Generation tools. • Advantages: • Increased user satisfaction • Improved requirements determination • Reduced applications backlog for IS dept. • Disadvantages: • Relatively inefficient, rarely scalable • May hamper updating systems & requirements

24. Other Approaches: Outsourcing • Contracting • Computer center operations • Telecommunications networks • Application development to external vendors

25. Systems-Building Methodologies • Structured methodologies • Structured analysis • Structured design • Structured programming

26. Structured Methodologies • Techniques are step-by-step, each step building on the last one. • Structured analysis • Structured design • Structured programming

27. Structured Analysis • Widely used to define inputs, processes, and outputs. • Logical, graphical model of information flow • Primary tool: Data Flow Diagram (DFD) • Process specifications describe the transformation occurring within the lowest level of the data flow diagram. They express the logic for each process.

28. Symbols for Data Flow Diagrams DATA FLOW PROCESS SOURCE OR SINK FILE

29. CUSTOMER FILE PAYMENT FILE Data Flow Diagram (DFD) GENERATE BALANCE GENERATE BILL GENERATE REPORT CUSTOMER  MANAGER

30. Structured Design • A set of design rules and techniques that promotes program clarify & simplicity. • Reduces effort of coding, debugging, etc. • Documented in a structure chart: • Top-down chart, showing each level of design & its relationship to other levels. Payroll Get valid inputs Calc. pay Write outputs Getinputs Validateinputs Calc. Gross pay Calc. Net pay Updatemaster Writechecks