Chapter 23 - Approaches To Software Development

Chapter 23 - Approaches To Software Development

1. Describe how a system was developed using RAD

   • It is an iterative development process. Users and developers take part in a regular workshop/ focus group. A prototype is developed alongside the user interface. This helps verify the requirements/ refine the data model. There are strict deadlines for each refinement. Functionality is prioritised as essential or non essential. If time runs out non-essential priorities will be dropped. CASE tools are usually used

2. Waterfall Module

   • Consists of a number of distnct stages eg analysis Each stage must be completed before moving onto the next stage. Each stage has deleiverables, If an error is found in one stage then it may have to be reworked

3. Prototyping

   • A first cut model is developed and evaluated by the users who provide feedback to the developers. The model is repeatedly refined and evaluated. The user interface is added and functionality is added. This is either refined into the final version (evolutionary) or used to specify the requirements (throwaway)

4. Describe the role of the end user in Waterfall model

   • The end user is involved in the analysis stage during fact finding. They are next involved in the acceptance testing to agree the system meets its specifications

5. Explain why custom built software would be preferred to off the shelf

   • Tailored to exact requirements instead of a general solution to suit many types of users. The development team will be available for training and maintenance

6. Describe three methods of fact finding used in the analysis stage.

   • Observation The users of the system are observed as they carry out their daily tasks
     • Questionnaire Users complete a set of pre-determined questions … which may be open or closed
       • Interview The users respond to spoken questions on a one-to-one basis The interview may be structured or unstructured
         • Document inspection Samples of orders/invoices/reports are examined … to identify inputs and outputs

7. Describe how end users are involved during other stages of the waterfall model.

   • The users will be involved in acceptance testing … where they use the system in a realistic environment … using real data/volumes of data … to ensure the system meets its objectives … by providing feedback to the developers
   • The user will be involved in the system review/maintenance … when the system has been in use for a short time … about errors discovered … and enhancements required