Unit 2 Flashcards
What is the difference between functional and non-functional requirements?
Functional requirements specify the behaviour of a system.
E.g. must accept a credit card number from a client
Non-functional requirements specify general properties.
E.g. must be reliable
What is the Volere template?
The Volere template is a template for a document that collates all the requirements of a system, together with other issues that may affect those requirements.
Which 4 parties make up the stakeholders of a system?
- The people who are going to use the system
- Those who are paying for it
- Those who are going to benefit from it
- Those who are developing it
What are the 3 categories of commonly cited problems with software products?
- System is delivered late and/or is more expensive than initially thought
- System does not deliver what the end users want
- System is unreliable and has errors
What are the 4 difficulties when specifying requirements?
- Requirements are not usually stable and tend to change as the environment changes
- There are usually many stakeholders and they do not always have the same view or priorities for the system to be developed
- It is not always clear and easy to identify what the requirements for a system are
- There are many factors that influence what the requirements are and these are not always explicit
RUN CCTV
What are the 5 properties of requirements that need to be checked?
- Realistic
- It should be possible to carry each requirement through to development
- Unambiguous
- There should be no alternative interpretations for one requirement
- Necessary
- Each requirement should fulfil a purpose
- Consistent
- Requirements should not contradict each other
- Complete
- The level of completeness of requirements will depend on the system to be developed and on the development environment
- Traceable
- It should be clear where each requirement comes from
- Verifiable and validated
- It should be possible to check that a requirement has been implemented, and that what is implemented corresponds to what was intended
In what 6 ways may requirements evolve?
- New requirements may be added
- Existing requirements may change because of changes in the environment or in the organisation
- Some requirements may become obsolete
- Technologies may evolve
- Other systems may emerge that introduce interoperability requirements
- Regulations may change
What is an agile approach to requirements engineering documentation?
In an agile approach, requirements documentation serves a purpose and should be done only to the extent that it contributes to that purpose. It should serve as a vehicle for common understanding, communication and future traceability.
What are requirements and stakeholders and how do they relate to each other?
Requirements are the functions and qualities that are wanted of a product.
Stakeholders are the people and organisations with a vested interest in the product.
Requirements arise from stakeholders’ needs.
What are the benefits of documenting requirements within a project?
Requirements record decisions and are the main reference for what should be built and the basis for validation of the built system. Therefore they need to be documented so they can be used throughout development.
What are functional requirements?
Functional requirements specify the behaviour of a system.
E.g. must accept a credit card number from a client
What are the 9 steps of the user story technique?
- User thinks of something they want the system to do
- Desire is written on an index card, and given a name and a number
- An estimate is made of how long it will take to realise the story in fully functional and releasable form
- Stories are factored (split into smaller stories) if:
- It appears they will take too long to implement as written
- One aspect of the story is more important than others
- They are long and rambling or overly general
- Stories are prioritised
- Stories are aggregated into collections, each collection defining the scope of work undertaken by the team this period
- Work products are validated and their ability to satisfy the original story is confirmed
- The user uses the developed system and new stories are conceived
- Iterate
Give three examples of functional requirements.
- The system shall accept a credit card number from a client.
- The system shall email the customer confirmation of their order.
- The system shall show the customer available products.
What is the benefit of user stories?
User stories emphasise communication between users, customers and developers.
What is the difference between user requirements and system requirements?
User requirements are abstract statements of the software requirements for the customer and end user of the system.
System requirements are a more detailed description of the functionality to be provided.