Chapter 1: The Systems Cycle Flashcards
Name the 5 methods of investigation to gather information?
- Questionnaires
- Interviews
- Meetings
- Observation
- Document Analysis
Give 2 advantages and disadvantages of questionnaires?
Advantages
- Ask a large number of people
- Responses can be anonymous
Disadvantages
- Designed carefully to avoid ambiguous questions
- Can’t guarantee a 100% return rate
Give the 8 stages of the system life cycle?
- Definition of the problem
- Investigation and analysis
- Design
- Implementation
- Testing
- Installation
- Documentation
- Evaluation and maintenance
What is prototyping?
A software development methodology
Gives the end user an incomplete, but working system
Can be changed following feedback from the client
What are the 2 types of prototyping and what do they do?
- Evolutionary
Prototype keeps being developed and evaluated by end user until system meets all requirements - Throw-away
Evaluated and then thrown away for quick feedback.
Give 2 advantages and disadvantages of prototyping?
Advantages
- Reduced time and costs
- Increased user feedback
Disadvantages
- End user may be confused with prototype and final system
- Takes a long time to develop prototype
What is RAD?
Rapid application development
Software development method to produce a software solution in less that 6 months
What are the 2 main features of RAD?
- Use of joint application design (JAD) workshops
Aims to develop requirements that should not change before the system is implemented - Use of timeboxing
Requirements defined in chunks that have a timescale that should not be exceeded. If the objective is not completed it can be added to another time box or dropped
Give 2 advantages and disadvantages of RAD?
Advantages
- End user involved at all stages
- End user involved in evaluations so final system should meet requirements
Disadvantages
- May meet requirements, but it may not function properly
- Project manager needs to keep tight control to meet 6 month deadline
What are the 3 specifications in the systems life cycle?
- Requirements specification
- System specification
- Design specificiation
Give 3 factors of the requirements specification?
- Defined functional requirements - what the end user wants the system to do
- Defined non-functional requirements - limitations for response time, hardware and software
- Timescale for the project
Give 3 factors of the system specification?
- Operation requirements- what operations the system should carry out
- Information requirements - what information the system should provide to end user
- Volume requirements - how much volume of processing is to be handled
Give 3 factors that the content of the design specification should include?
- Purpose of the system
- Inputs and outputs - documents and interface
- Validation rules and error messages
What are the 3 types of test data?
- Normal
- Extreme
- Erroneous
Give 3 things a test plan should cover?
- Requirements
- Pathways
- Validation
Name the 5 members of a project team and what they do?
- Project manager - plans whole project & solves problems
- Systems analyst - analyse old system
- Systems designer - uses analyst to design new system
- Programmer - creates code for software for the system
- Tester - develops test plans to ensure no bugs or errors
What is an entity relationship diagram and what 5 aspects does it have?
ERD represents the structure of data in a system
- Entities - real life object that can be uniquely identified
- Attribute - feature of an entity
- Primary key - a unique field in a table
- Foreign key - a primary key in another table
- Relationships - how entities are linked - 1:1, 1:M, M:M
What is a data flow diagram and what 3 aspects does it have?
DFD shows how data moves through a system
- Shows what system interacts with by external entities
- Shows the data stores used
- Has rules about which components can be linked
What is a flowchart and what 3 aspects does it have?
Flowchart is a graphical representation of processes involved in a system
- Uses different shaped symbols to represent actions
- Breaks down a process into small steps
- Easily understood by anyone even if they don’t work in IT
What is a critical path analysis and what 3 aspects does it have?
CPA shows the relationship between tasks in a system, showing how timings will fit together so it can be completed in a logical order
- Identifies logical order to be completed in maximum time
- Ensures project completed on time with lag time if slip up
- Enables resources to be allocated
What is a gantt chart and what 4 things does it contain?
Gantt chart is a diagram that shows how long each task will take and the order
- Milestones - important checkpoints
- Resources - people and equipment needed
- Status - progress of each task
- Dependencies - tasks may be dependent on each other
Identify the 5 flow chart symbols?
- Start/end - oval
- Input - oval with semi circle missing from right side
- Output - square with wavy bottom
- Process - square
- Decision - diamond
Give 2 benefits of interviews?
- Questions can be adjusted or added
2. Rapport can be developed with the people who will use the system
Give 2 disadvantages of interviews?
- Time consuming and costly
2. May be impossible to interview everyone in a large organisation