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
Give 2 benefits of meetings?
- Body language can be seen
2. Can be used to gather or give information
Give 2 disadvantages of meetings?
- Discussion may lose focus so questions may not be fully answered
- Some staff may not attend if other work needs to be completed
Give 1 benefit of document analysis?
Good for obtaining factual information such as inputs and outputs of a system
Give 1 disadvantage of document analysis?
Cannot be used when input, output and other information is not document based
Give 2 advantages of observation?
- Work loads, methods of working, delays and bottlenecks can be identified
- Effects of office layouts and working conditions can be assessed
Give 2 disadvantages of observation?
- Problems may not occur during observation
2. Users may act differently due to nerves or put on a performance when being observed
What 3 things will the analyst use to select the most appropriate method of investigation?
- People
- Type of information
- Place in which information is being gathered
What is the systems life cycle?
The stages that need to be completed to create a new or modified system. The cycle will have to be repeated after time
In 2 steps, explain what the definition of the problem stage is?
- Initial look at the existing system to see if it can be improved and if it meets end user requirements
- For the project to continue, the new system must be viable in terms of hardware, software, budget and time scale
In 3 steps, explain what investigation and analysis is?
- Investigation is were information is gathered by the 5 methods
- The results are analysed to gather a full understanding of problems
- User requirements are defined and agreed with client
What happens during the design stage?
Follows the requirements specification set in the investigation and analysis stage
The methods and formats of data capture, input, outputs, validation routines, queries and reports are all designed
Describe in 3 steps the implementation stage?
- Using the design to build the system
- A decision about software strategy based on the budget is made
- Coding, macros and queries are created with backup and storage of data considered
What happens in the testing stage?
A test plan is followed, with results recorded to ensure that the system is free of errors and that it meets user requirements
Describe what happens during the installation stage?
The system is installed for the client and the installation strategy is chosen and training is carried out
Name 4 things created during the documentation stage and then passed to the end user?
- Test plans
- User manuals
- Program specification
- Security and version details
Give 2 things that the evaluation and maintenance stage may do which shows its iterative nature?
- Forms the basis for the decision if to begin the system life cycle again
- The solution should be evaluated after implementation and maintained to ensure that it continues to meet needs of end user
Who in the project team creates the test plans?
The systems designer
Name 3 things the project manager does?
- Plans and controls the whole project, rectifying any problems
- Consults with the project team and end user, creating a deadline and budget at the start of the cycle
- Responsible for ensuring each stage is complete before moving onto the next
Name 3 things the systems analyst does?
- Analyses the existing system and creates a plan of inputs outputs, hardware software and training
- Develops the feasibility report
- Liase with the staff in the organisation and they know the current system the best
Give 1 thing the systems designer should do?
- Build on analysts findings to plan and design the new system
Give 3 things the programmer should do?
- Creating the code for the software for the system
- They can be specialist in one language or many
- Create the technical documentation
Give 3 things the tester of the project team should do?
- Carry out the test plan to find bugs and errors to correct them, ‘deliberately’ trying to break the system
- Ensure a range of test data e.g. normal erroneous and extreme is being used
- Record the results in the test plan to go in the technical document
