Scenario-Based Requirement Analysis

Method created by Alistair Sutcliffe (1998)

Presented by Belfrit Victor Batlajery (2012)

HISTORY OF THE METHOD• Alistair Sutcliffe

– Professor of systems engineering and director of the Center for HCI Design, School of Informatics, City University, London, UK

• 1997 SCRAM– SCRAM combines 3 things

• (concepts of demonstrator; Scenario; Design rational)

– SCRAM only gave an outline guidance for Scenario-based analysis

• Still to broad

• 1998 2nd Generation of SCRAM– Integration scenario with model-based requirement anlysis

• Definition :“facts describing an existing system and its environment including the

behavior of agents and sufficient context information to allow discovery and validation of system requirements”

• Scenario Script : Derived from Inquiry Cycle – Ex : storyline on events

• Scenario-based model : is created to describe system environment– Later will be cross-check with content of system in

Scenario Script

• Scenario maybe imaginary or real example and captured in text narratives, sketches, or informal media.

SCENARIO

• Definition :“Artifact that emerge during Requirement Engineering process evolving

from simple function desiderata to model function that constitute requirement specification”

REQUIREMENT SPECIFICATIONS

Requirements

Specification

What we need ?

What we need ?

What we need ?

Inbound Event Analysis

Inbound Event Analysis

2

GOAL ANALYSISGOAL ANALYSIS1

UsersUsers

Scenario scripts

Scenario scripts

aims, goals

Usage scenarios

Example problem

s

System FunctionRequirementspecificationRequirementspecification

goal lists

Requirement F

unction

Input Event

user, env, event

syst

em m

odel

Interaction user and proposed systemLead to

First cut decision (automation and user-system boundary)

Characterize system outputCharacterize

system output3

Initial system modelsystem output types

Direct Commands,

Indirect commands,

Input requests,

Information displays,

Metaphors and interactive worlds

Output requirement

analysis

Output requirement

analysis

4

Social impact analysis

Social impact analysis

5

Information

requirement

Requirementsspecification

Requirementsspecification

Stakeholder analysis

Stakeholder analysis

6Agent destination

Scenario structure model

Scenario structure model

Refined requirements

6 STEPS

6 STEPS

• GOAL ANALYSIS

• INBOUND EVENT ANALYSIS

• CHARACTERISE SYSTEM OUTPUT

• OUTPUT REQUIREMETS ANALYSIS

• SOCIAL IMPACT ANALYSIS

• STAKEHOLDER ANALYSIS

Process Description

Process Description

• Study case : – London Ambulance Service–Computer Aided

Dispatch (LAS-CAD)

• Reasons : – Unique software system (real-time). it is driven by

asynchronous events and also it has to deal with timeline

• Solution : – timed automata approach – message sequence chart

• Source : – Saiedian et al. (2005) ; – Regnell, Andersson and Bergstrand, (1996)

REAL-TIME SCRA

EXAMPLE Two users (student and company).

GOAL ANALYSIS

• Data about job seeker • Application documents • Companies profile • Job description • Extra information • Bank Information

NORMAL EVENT + ABNORMAL EVENT

CATEGORIZE + ANALYSE SYSTEM OUTPUT

ANALYZE SOCIAL IMPACT

STAKEHOLDER ANALYSIS

Q.U.E.S.T.I.O.N.S

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