Analysis Flashcards
Describe how document sampling can be used during fact-finding
It is used to see how data flows through the organisation
it looks at how data is input, processed and reported.
typical documents are data collection forms, invoices or orders.
Suggest and justify two criteria which the systems analyst might use when selecting the personnel to be interviewed.
1) a representative sample of users from each department so that the views of as many users as possible may be obtained
2) representatives from the organisation’s management so that overall business views can be obtained from experts
State two disadvantages of interviewing
Subjects can be intimidated by formality of interview
It can be difficult to devise questions in advance
Name and describe four methods of factfinding
Questionnaires- set of questions developed asking key points about current system. Completed by wide selection of users
Observation- systems analyst shadows key users and records their everyday activities
Interviews- set of questions developed asking key points of current system. Asked to a selection of key users
Document sampling- analyst examines a selection of key input forms that are currently in use.
What is the difference between functional and non-functional requirements, using examples from a stock control system.
Functional requirements specify what a software MUST do, eg. when the stock level falls below its re-order level, a re-order request is automatically generated
Non-functional requirements specify additional criteria by which the system will be judged, eg. the sale on an item at the POS terminal should be recorded to the database in x seconds.
What is a functional requirement?
A requirement of the system that enables a user to perform a specific function.
What is a non-functional requirement?
A requirement of the system that reflects the qualities that the user would like to have in the system.
What is the purpose of a DFD
It provides a graphical presentation of a system at different levels of how a system interacts with external entities
It identifies data stores.
Describe how a system could be developed using prototypes
A first cut model is created then evaluated by the user who provides feedback to the developer so that a refined model can be created
The prototype may evolve into the final system- evolutionary prototyping or the prototype may be discarded once the system objectives have been established- Throwaway prototyping.
How could the end user be involved during the implementation stage?
New system will be installed at users site
End user may require training
User will evaluate new system
What happens during the user requirement stage?
The system analyst identifies the functionality and requirements required of the system from end users. Uses fact finding methods such as interviews
What happens during the implementation stage?
The system is developed from technical specification, software is produced, new system is installed, system is tested, staff trained
Explain how a level 1 DFD could be produced from a context level DFD.
Main process will be expanded on into the main sub process
Data stores will be identified
Data flows will be identified
