Systems Analysis Midterm Lesson
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The document outlines the phases of a feasibility assessment for a new system. It describes techniques for gathering data like interviews, questionnaires, and observations. Common tools for data analysis include ER diagrams, DFDs, and decision tables. Requirements and recommendations are reported to management. The design phase considers building vs buying options and acquiring hardware/software. Input/output, file, database, and program designs are created. The development phase includes programming and testing. Implementation involves training, equipment conversion, file conversion, and system conversion options. Auditing, evaluation, and ongoing maintenance are also discussed.
Systems Analysis Midterm Lesson
- 1. Feasibility Assessment Phase 2: Analysis Data Gathering A number of techniques can be used: Interviews with users and managers- Structured interview – includes only questions that have been written out in advance. Unstructured interview – interviewer has a general goal but few, if any questions prepared. Examining current business and systems documents and output- may include current order documents, computer systems procedures and reports used by operations and senior management. Sending out questionnaires . Observation of current procedures- by spending time in various departments; a time and motion study can show where procedures could be more efficient, or to detect bottlenecks.
- 2. Data Analysis Typical tools for data analysis- Entity Relationship diagram. Data flow diagram. Decision table/Decision Tree. Written report. Report to management/ customer/ client. Entity-Relationship Diagrams (ERD) Data Flow Diagrams (DFD)
- 3. Decision Table System Requirements & Recommendations A detailed list of things the system must be able to do: Highlight problems with current system. The design of the new system will be based on these requirements. Analyst and management must come to a clear agreement on requirements. List of possible solutions. Hardware/software recommendations.
- 4. Report to Management Summarizes the problems found in the current system. Describes the requirements for the new system, including a cost analysis. Makes a recommendation on what course to take next. Pre-Design considerations Phase 3: Design Build or Buy? Custom Software. Developed by user. Developed at user request by outside vendor. Packaged Software. Horizontal. Many org types.
- 5. Vertical. Industry specific. Acquire Hardware/Software Technical specifications. Solicit vendor proposals. Test & evaluate. Benchmark Test. Make a decision. Input: Things to consider. The medium of the output. Example paper, screen, etc. The types of reports needed and what data is needed for the reports. Output: Things to consider. The input medium. Example, captured at the source, keyed from source document. The fields needed, how they are laid out on the input screen, etc. Input validation may be necessary Input/Output Design
- 6. Files and Databases Things to consider. How files are organized. Sequentially, directly, or by another method. The format of the records making up the data files. Database Design Table structure definitions & relationships. Security. Program Design
- 7. Phase 4: Development Programming Prepare program design specifications Use logic flowcharts and pseudocode to facilitate code development Testing Unit testing – verifies that individual program units work. Perform testing with test data. System testing – determines whether all program units work together as planned. Volume testing – uses real data in large amounts. Determines whether the system can handle a large volume of data. Phase 5: Implementation Training Teach users how to use the system. The system will do no better than the people using it. Develop user’s manual to aid users who are not familiar with the system. Hands-on training is best. Equipment Conversion Items to consider. Delivery schedules must be coordinated. Terminals or personal computers must be networked. Devices on the system must be compatible.
- 8. File Conversion If existing files are manual, they must be keyed in or scanned into the system. Manual files must be kept current while data is being input into the new system. If existing files are computer-based, programs must be written to convert the files into the format needed for the new system. System Conversion Four approaches. Direct conversion – the user simply stops using the old system and starts using the new one. Phased conversion – the system is implemented one part at a time. Pilot conversion – the entire system is used by a designated set of users. Parallel conversion – the old and new systems are both used until users are satisfied the new system works. Conversion Options Auditing Systems to trace data in the system back to a source document. Very helpful in tracing security violations. Evaluation Determines how well the system is meeting the original requirements, benefits, and budgets. Evaluation can be performed by the analyst and someone from the organization. Evaluation can also be performed by an independent third party.
- 9. Maintenance An ongoing activity that lasts the lifetime of the system. Several types of maintenance activities Enhancements to the system. Fix bugs in the system as they are identified.