Scenario advisor tool for requirements engineering

Abstract

This study investigates the usefulness of a scenario advisor tool which was built to help requirements engineers to generate sufficient sets of scenarios in the domain of socio-technical systems. The tool provides traceability between scenario models and requirements and helps to generate new scenarios and scenario variations. Through two series of evaluation sessions, we found that the scenario advisor tool helped users to write more sound scenarios without any domain knowledge, and to generate more variations on existing scenarios by providing specific scenario-generation hints for each scenario component. The tool should improve the reliability of requirements elicitation and validation.

Appendices

Appendix A

1.1 Scenario taxonomy tables

Actor area
Component	Definition	Synonym	Property
Activity	Manifestations of behaviour; reported history; collections of action; higher order units	Behaviour (ref. task)	Complexity, physical/cognitive activity
Agent	A human or machine that carries out a task; one that acts or has the power or authority to act; has sub-types of human and machine agents	Actor, Artefact	Human agent: capability, expertise, motivation, aptitude, responsibility, authority, trust
			Machine agent: reliability, task support, usability, utility
Attribute	Information or data that describes an agent or object	Characteristic, feature, quality, property	N/A
Group	An informal or temporary assembly of agents	Cluster, formation	Capability, motivation, authority, trust
Organisation	The persons (or committees or departments, etc.) who make up a governing body and who work together; it has a leader	Constitution, unit, structure, group	Capability, motivation, authority, trust
Physical structure	Something physical which is made up of a number of parts that are held or put together in a particular way.	Authority, compound, object container	Size
Role	The characteristic and expected social behaviour of an agent	Function, occupation, position	N/A

Intention area
Component	Definition	Synonym	Property
Goal	The purpose toward which an endeavour is directed; future intent	Intention, purpose, aim	Importance, quality
Objective	Something worked toward or striven for; higher order goal	Intention, target	Importance
Plan	A descriptive specification of plans	Strategy, approach	Effectiveness, clarity
Policy	A plan or course of action, as of a government, political party, or business, intended to influence and determine decisions, actions, and other matters; a set of statements used to guide, a principle, or procedure considered expedient, prudent, or advantageous	Principle, mission	Effectiveness, clarity

Task area
Component	Definition	Synonym	Property
Action	The process of acting or doing that results in change in the world; a physical change, as in position, mass, or energy, that an object or a system undergoes; actions are either continuous or discrete; actions have a duration.	Behaviour, activity, procedure	Complexity, duration, physical/cognitive
Event	Something that takes place; events can be contained in a message	Occurrence, happening	N/A
Object	Physical or conceptual thing that exists over time and is either changed by a task or changes other objects. In object-oriented programming, objects include data and the procedures necessary to operate on that data	Entity	Physical/conceptual
Procedure	A set of instructions that performs a specific task; a subroutine or function	Method, course of action, process	N/A
Resource	Something that can be used for support or help; an available supply that can be drawn on when needed; the ability to deal with a difficult or troublesome situation effectively	Means, tools, capability, materials	N/A
State	A type of attribute of an object, an agent, or a task.	Condition	N/A
Task	A piece of work assigned or done as part of one’s duties; a function to be performed; an objective.	Duty, procedure, method	Predictability, complexity, reliability

Environment area
Component	Definition	Synonym	Property
Social environment	Social circumstances surrounding an agent or group of agents	Community, public factors	Management culture, time pressure, stress
Economic environment	Economic circumstances surrounding an agent or group of agents	Cost, financial factors	N/A
Physical environment	Physical circumstances surrounding an agent or group of agents	Tangible context	Weather state (wind, cloud, etc.), climate, noise, interruptions, fatigue, stress
Location	Identifying the position of a plan, an act, or a site, etc.	Place, situation, locality	N/A
Situation	Complex state description of context for activity and background circumstances	Circumstance, state, condition	Logical/physical state, temporary, critical
Time	A non-spatial continuum in which events occur in apparently irreversible succession from the past through the present to the future; an interval of time characterised by properties and the occurrences of certain conditions, events, or phenomena	Period, duration	Time period, time point, scale
Environment	Social, economic, and physical environment	N/A	N/A

Communication area
Component	Definition	Synonym	Property
Argument	A discussion about a topic or design problem, often with positions for and against; a controversial communication.	Opinion, assertion, claim, dispute	N/A
Assumption	Something taken for granted or accepted as true without proof; a hypothesis that is taken for granted.	Hypothesis, supposition	N/A
Attitude	An opinion, a state of mind or a feeling; disposition	Approach, mind-set, posture, belief	N/A
Causation	The act or agency or process of causing, by which an effect is produced	Causality, cause, reason, source	N/A
Consequence	A logical or natural conclusion or a result which follows from an action or condition	Effect, outcome, result	N/A
Constraint	Something that controls decisions, prevents or restricts actions of others	Restriction, limitation, check	N/A
Context	The circumstances and events surrounding or leading up to an event or occurrence	Circumstance, setting	N/A
Decision	A judgment or conclusion on an issue, or making up one’s mind	Conclusion, judgment, assessment, evaluation	N/A
Evidence	A proof or an example helpful in forming a conclusion or judgment	Proof, data, verification	N/A
Interpretation	Explaining the meaning of; making sense of	Decoding, understanding, explanation	N/A
Issue	An important question that is in dispute and must be settled	Subject, topic	N/A
Justification	The act of justifying; a fact or circumstance that shows an action to be reasonable or necessary	Validation, good reason, explanation	N/A
Position	A point of view or attitude on a certain question; social standing or status; a situation as it relates to the surrounding circumstances; it separates viewpoints from alternative arguments	Situation, standpoint, status, purpose	N/A
Solution	The method of answering questions; solves a problem; achieves a goal	Result, explanation	N/A
Viewpoint	A position from which something is observed or considered	Perspective, opinion	N/A

Appendix B

2.1 Scenario schema diagrams

Scheme 1

Actor area

Scheme 2

Intention area

Scheme 3

Task area

Scheme 4

Environment area

Scheme 5

Communication area