Hoofdstuk 3 - Requirements

Question 1

Why should the requirements specification be understandable, precise and open?

Answer 1

◦ Understandable: so that we can decide what is in- and out scope
◦ Precise: So that parties agree what’s inside and outside the system
◦ Open: So that developers have enough freedom to pick an optimal solution

Question 2

What’s the relationship between a use case and a scenario?

Answer 2

◦ A use-case describes outwardly visible requirements of the system.
◦ A scenario is an instance of a use-case, showing a typical example of its execution. Scenario shows how objects interact to achieve the use case goal.

Question 3

Can you give 3 criteria to evaluate a system scope description? Why do you select these 3?

Answer 3

◦ It should be short, it should be written down and it should have end-user commitment.
◦ Short because long statements are not convincing. Written down, so we can reference it later when prioritizing use cases.

Question 4

Why should there be at least one actor who benefits from a use case?

Answer 4

Because the corresponding stakeholder will argue to keep the use case in the requirements.

Question 5

Can you supply 3 questions that may help you identify actors? And use cases?

Answer 5

◦ Actors:
▪ Who uses the system?
▪ Who installs the system?
▪ Who maintains the system?
◦ Use cases:
▪ Who gets information from this system?
▪ Are there any external events the system must know about?
▪ What functions will the actor want from the system?

Question 6

What’s the difference between a primary scenario and a secondary scenario?

Answer 6

◦ A primary scenario is the scenario where we assume everything goes right (=success)
◦ The secondary scenarios are to detail what happens during special cases (=errors, alternative paths)

Question 7

What’s the direction of the «extends» and «includes» dependencies?

Answer 7

◦ Extends is inwards or towards the current use case
◦ Includes is outwards

Question 8

What is the purpose of technical stories in scrum?

Answer 8

Technical stories express non-functional requirements in story form

Question 9

List and explain briefly the INVEST criteria for user stories.

Answer 9

◦ Independent: stories should not have dependencies on other stories
◦ Negotiable: too much detail on story limits conversation with the customer
◦ Value: each story must be of value to the customer
◦ Estimate: stories should be small enough to estimate
◦ Small: it should be completed in one iteration
◦ Testable: acceptance criteria should be available

Question 10

Explain briefly the three levels of detail for Product Backlog Items (Epic, Features, Stories)

Answer 10

◦ Epic means its bigger than a release, it means it would take months to finish
◦ Features mean its bigger than a sprint. It would take some weeks to finish
◦ Sprintable stories would be ready in one sprint so it only takes some days to finish it.

Question 11

Define a misuse case

Answer 11

it describes the process of executing a malicious act against a system, while use case can be used to describe any action taken by the system