7 The systems life cycle
Candidates should be able to:
7.1 analysis
• methods of researching an existing system – identify and describe methods of researching an existing system (e.g. observation, interviews, questionnaires and examination of existing documents) – discuss the disadvantages and advantages of the different methods
• recording and analysing information about the current system – describe the need to identify inputs, outputs and processing of the current system – describe the need to identify problems with the current system – describe the need to identify the user and information requirements for the new system
• system specification – identify and justify suitable hardware for the new system – identify and justify suitable software for the new system
7.2 design
• describe how it is necessary to design documents, files, forms/inputs, reports/outputs and validation • produce designs to solve a given problem
• design data capture forms and screen layouts
• design report layouts and screen displays
• design validation routines (including length check, type check, format check, presence check, check digit)
• design the required data/file structures (e.g. field length, field name, data type)
7.3 development and testing
• testing designs – describe how data/file structures are created and tested – describe how validation routines are created and tested – describe how input methods are created and tested – describe how output formats are created and tested
• testing strategies – describe the need to test each module – describe the need to test the whole system – describe testing using normal data including definition and examples – describe testing using live data including definition and examples – describe testing using abnormal data including definition and examples – describe testing using extreme data including definition and examples
• improvements needed as a result of testing – describe how it may be necessary to improve the system and make changes (e.g. data/file structures, validation routines, input methods, output formats may need to be amended/ improved)
7.4 implementation
• different methods of system implementation – describe the four methods of implementation (direct changeover, parallel running, pilot running, phased implementation)
• methods of implementation – identify suitable situations for the use of different methods of system implementation (e.g. organisations or departments within organisations which need a quick changeover, organisations or departments within organisations which cannot afford to lose data) – describe advantages and disadvantages of each method of implementation
7.5 documentation
• technical documentation for an information system – explain the need for technical documentation – identify the components of technical documentation (e.g. purpose of the system/program, limitations of the system, program listing, program language, program flowcharts/algorithms, system flowcharts, hardware and software requirements, file structures, list of variables, input format, output format, sample runs/test runs, validation routines)
• user documentation for an information system – explain the need for user documentation – identify the components of user documentation (e.g. purpose of the system, limitations of the system, hardware and software requirements, how to load/run/install software, how to save a file, how to print data, how to add records, how to delete/edit records, input format, output formats, sample runs, error messages, error handling, trouble-shooting guide/help line, frequently asked questions, glossary of terms)
7.6 evaluation
• describe the need to evaluate a solution in terms of the efficiency of the solution, the ease of use of the solution, and the appropriateness of the solution
• describe the need for a variety of evaluation strategies, e.g. – compare the solution with the original task requirements – identify any limitations and necessary improvements to the system – evaluate the users’ responses to the results of testing the system