GOALS IN REQUIREMENTS ENGINEERING

10 minute refresher on Goal Trees and their use in Requirements Engineering

Transcript

1. GOALS IN REQUIREMENTS ENGINEERING
2. Score Points Score Points Get to Home Base Get to Home Base No Shrubberies in front of the Home base No Shrubberies in front of the Home base No alligator’s head in the Home base No alligator’s head in the Home base Not Occupied Not Occupied Travel Across River Travel Across River Get to River Bank Get to River Bank Hops Across Highway Hops Across Highway Dodge Traffic Dodge Traffic Dodge Left bound traffic Dodge Left bound traffic Dodge Right bound traffic Dodge Right bound traffic Jump on Turtles Jump on Turtles Turtle Above water Turtle Above water Red Red Light Blue Light Blue Forward/Backw ard/Sideways Forward/Backw ard/Sideways Jump on Logs Jump on Logs Dodge Snake’s Mouth Dodge Snake’s Mouth Forward/Backw ard/Sideways Forward/Backw ard/Sideways Jump on Alligator Jump on Alligator Not in Alligator’s Mouth Not in Alligator’s Mouth Forward/Backw ard/Sideways Forward/Backw ard/Sideways http://www.happyhopper.org/
3. Questions… • What is a Goal Tree? • What is a Goal? • Why are they useful for RE? • How do you identify them?
4. What is a Goal Tree? Graphical representation of the reduction of problems (or goals) to sub-problems (or sub-goals). And Or Trees - http://en.wikipedia.org/wiki/And%E2%80%93or_tree
5. What is a Goal? A goal is an objective the system under consideration should achieve. “Goal-Oriented Requirements Engineering: A Guided Tour” - Axel van Lamsweerde
6. What’s the link? • The use case is a collection of scenarios that together accomplish a specific user “goal”. - https://eee.uci.edu/12s/37110/slides/Cases.pdf
7. Why are they useful for RE? • Eliciting and Identify requirements • Structuring requirements • Explaining Requirements to Stakeholders -since they are graphical representations. • Managing Conflicts -Different stakeholders will have different goals and sometimes they will conflict.
8. How do you identify goals? • Software systems are built to solve problems. -Try finding that List (of Problems) • Look for keywords that convey intent in the documentation that you might have about your projects. • Refinement- HOW • Abstraction - WHY • Conflict and Obstacle Resolution
9. Types of Problems (Goals) • Functional Goals • Satisfaction Goals • Information Goals • Non-Functional Goals • Accuracy Goals • Performance Goals • Time • Response Time • Through-put • Space • Security • Confidentiality • Integrity • Availability
10. HOW & WHY - Refinement and Abstraction Why? Why? Score Points Score Points Get to Home Base Get to Home Base No Shrubberies in front of the Home base No Shrubberies in front of the Home base No alligator’s head in the Home base No alligator’s head in the Home base Not Occupied Not Occupied Travel Across River Travel Across River Get to River Bank Get to River Bank Hops Across Highway Hops Across Highway Dodge Traffic Dodge Traffic Dodge Left bound traffic Dodge Left bound traffic How? How? Dodge Right bound traffic Dodge Right bound traffic How? How? Jump on Turtles Jump on Turtles Turtle Above water Turtle Above water Red Red Light Blue Light Blue Forward/Ba ckward/Side ways Forward/Ba ckward/Side ways Jump on Logs Jump on Logs Dodge Snake’s Mouth Dodge Snake’s Mouth Forward/Ba ckward/Side ways Forward/Ba ckward/Side ways Jump on Alligator Jump on Alligator Not in Alligator’s Mouth Not in Alligator’s Mouth Forward/Ba ckward/Side ways Forward/Ba ckward/Side ways http://www.happyhopper.org/
11. Class Activity • List out the problems that you think you are trying to solve in your respective projects. First do this individually without discussing much with your teammates. Look for the intent-keywords (15 mins) • Compare the problems that you listed out and form a consolidated list. See if you have missed out on any problems. (5 mins) • Now, take the list and form a Goal Tree, using the WHY and HOW questions. Again, first do this individually without a great deal of discussion. (15 mins) • Compare the goal trees. Again, consolidate it into a single goal tree. (10 mins)