The document discusses different approaches to systems building, including the traditional systems lifecycle model consisting of definition, feasibility, design, development, testing, implementation, evaluation and maintenance phases. It also covers prototyping, using application software packages, end-user development, outsourcing, structured methodologies, object-oriented development, computer-aided software engineering and software reengineering.

1. DIFFERENT APPROACHES TO SYSTEMS BUILDING

4. System Lifecycle

13. Prototyping process of building experimental system to demonstrate, evaluate approach. an iterative process best for design of end-user interface

15. Application Software Packages prewritten, precoded application software, commercially available for sale/lease customization geared to common requirements

16. Modifying Software Package to meet organization’s unique requirements without destroying the integrity of package Application Software Packages Customization Raises Development Cost

17. Effects of Customizing Software on Total Implementation Costs Application Software Packages 0 2 4 6 8 10 0.5 1 2 3 4 5 % LINES OF CODE CONVERTED TOTAL IMPLEMENTATION COSTS

19. End-User Development end-users develop information system with little help from technical specialists using 4 th generation tools

22. “ Outsourcing”

25. System Building Methodologies

29. PROGRAM FLOWCHART SYMBOLS: BEGIN OR END DIRECTION PROCESS DECISION INPUT OR OUTPUT SUBROUTINE MANUAL OPERATION CONNECTOR

30. PROGRAM FLOWCHART: PROCESS A PROCESS B SEQUENCE PROCESS C PROCESS D R TRUE SELECTION PROCESS E S TRUE ITERATION

31. This flowchart shows the software development cycle. You basically design the system, code it and test it. When an error is found, it must be determined whether the error is a design error or not. Coding errors can quickly be fixed, but design errors may take longer.