- Output specifications
- Input specifications
- File/data stores
- Hardware and software requirements
- Processing specification
1. Output Specifications
The following factors should be considered when designing the output;
- The target audience: audience can either be the top management, the staff and any other relevant stakeholders
- The frequency of report generation: this is the rate at which the report are required. It can be daily, weekly, monthly or yearly. In our case study, our reports are required termly and yearly
- Quality and format: our outputs should be of a higher quality than the existing system and the layout and format also considered
2. Input Specifications
3. •File/Data Stores
Factors to consider when designing a file:
- The key attribute or field
- The type of data
- The length of each field
- Backup and recovery strategies
4. Hardware and Software Requirements
- Economic factors such as price and acquisition method
- Operational factors e.g. reliability, upgradeability and compatibility with existing resources
- This is the process of transforming requirements specification into a logical view of the system. Pictorial representation tools or a design specification language are used such tools include the system flow chart. Other algorithm design tools like pseudocodes, flow chart, Data flow diagram (DFD), Data dictionary, Structured English, Decision table and Decision tree that can be used to extract the processing logic for each module in the system before construction. Design elements describe the software in sufficient detail that the developer can build the software with minimal additional input.The technical specialists begin to translate the requirements into specific design solutions that will create the systems, features, and functions that are necessary to achieve the business and functional requirements. In the previous requirements definition phase, the focus was on defining specific capabilities desired by and in support of the organization, and its customers and end-users. In the system design phase the attention turns to defining systems and technical requirements.
Guidelines for drawing a system Flowchart
- Start by writing the title of the flowchart
- If possible, start drawing the flowchart with trigger event
- Note down the successive actions taken in their logical order until the event or process is concluded. Use a few words to describe the actions
- When there are many alternatives at the decision stage, follow the most important and continue with it. Other significant but less important alternatives can be drawn elsewhere and reference made to them by using the on or off page connectors
- What do you need for input?
- How many decisions are available and how can they be implemented
- Which entities need processing? How will the processing done?
- Which files need updating? How will the updating done?
- What are the expected outputs? How will they be implemented?
Stage 5: System Construction
- System construction refers to the coding, installation and testing of the modules and their components such as outputs, inputs and files.
- The purpose of the construction phase is to develop and test a functional system that fulfills the business and design requirements.
- Using the high level structured languages such as Pascal, Cobol etc.
- Using fourth generation languages (4GLS) – these are easy to use programming languages. Some of the fourth generation languages are Visual Basic, Visual Cobol, Delphi Pascal etc.
- Customizing the standard packages – this involves the use of a ready made software package mostly a database software, financial package or enterprise management system.
- After construction has been conducted, sample data records are appended to the system to test its integrity and or whether it produces the required outputs.
- The system is tested using the requirement specifications and the design specifications to find out whether it meets all requirements specified.