1

Week 5

by A.Nosseir

Requirements Gathering

Dr. Ann Nosseir

Week 5

by A.Nosseir

Focus of Investigation (User)

• The users: Who they are; – real (primary) users, – stakeholders (secondary users) , people or group

who are not primary users but who are affected or influenced in some way by the computer system or who affect or influence its development • (e.g. senior managers, business analysts, system

analysts, project managers, application developers, interface designers)

Week 5

by A.Nosseir

Focus of Investigation (User)

• Characteristics of the users:–Age, sex, culture, physical abilities and

physical disabilities, educational background, computer/IT experience, motivation, attitude, enjoyment, & satisfaction

Week 5

by A.Nosseir

Focus of Investigation (Task)

• Characteristics of the tasks: Are the tasks easy, complex, novel, variable, repetitive, frequent or infrequent, single tasks or multitasking, time critical, requiring individual or collaborative working? Are there safety issues in relation to the work?

2

Week 5

by A.Nosseir

Focus of Investigation (Environment)

• The domain: Wider specialist knowledge, & specific knowledge for a computer system

• Physical environment: Noise, stress, comfort, dirt, dust, heating, lighting, ventilation, furniture, working space, individual offices, open-plan areas, equipment layout, hazards in the workplace

• Social environment: Pressure of work, individual or collaborative working, individual offices or open-plan areas

Week 5

by A.Nosseir

Focus of Investigation (Environment)

• Organizational environment: Organizational mission and aims, organizational attitude to IT, organizational policies, job design, and roles

• User support environment: Availability of training, availability of colleagues/experts, availability of manuals or online help

Week 5

by A.Nosseir

Focus of Investigation (Other)

• Qualitative usability aspects: General, often unquantifiable goals, such as easy to learn, UI intuitiveness

• Quantitative usability goals: Measurable goals, such as usability metrics

• Constraints: Costs, timescales, budgets, technology hardware and software

• Trade-offs: Conflicting/contradictory requirements

Week 5

by A.Nosseir

Users Characteristics

3

Week 5

by A.Nosseir

Users Characteristics

Week 5

by A.Nosseir

Users Characteristics

Week 5

by A.Nosseir

Users Characteristics

Week 5

by A.Nosseir

Translating UC into Requirements

4

Week 5

by A.Nosseir

The Domain

• We need to

– Understand the Domain

– Represent the Domain

Week 5

by A.Nosseir

Understanding the Domain

• Domain Analysis

– Talking to, observing, interviewing domain experts

– We have to know that knowledge acquisition is often informal

– So, we need iteration of observation/ interviews/ analyses

Week 5

by A.Nosseir

Representing the Domain

– Flow model

– Sequence model

– Artefact model

– Cultural model

– Physical model

Week 5

by A.Nosseir

Flow model

• Components of flow model – Individuals

– Responsibilities

– Groups

– Flow – how people communicate to get work done

– Artefacts

– The communications topic or action-request a room

– Places -meeting room

– Breakdown (Benyon et al p.459)

5

Week 5

by A.Nosseir

Figure 18.1 Constructing a flow model, step 1.

Week 5

by A.Nosseir

Figure 18.2 Constructing a flow model, step 2.

Booking

Bill

Week 5

by A.Nosseir

Figure 18.3 Constructing a flow model, step 3.

Booking

Bill

bill

May be not ready to check out

Week 5

by A.Nosseir

Sequence Model

• Components of the model

– Intent (purpose)

– The trigger that causes the sequence of actions

– A series of steps which achieve the intent

– Any breakdowns or problems

6

Week 5

by A.Nosseir

Sequence Model

Intent :satisfy booking

request

Trigger : An email arrival with a

request of booking

Read request note

Check room availabilityIntent :fill highest

price first Most suitable room is

booked Make provisional booking

See Pages 464- 467

(Benyon et al)

Week 5

by A.Nosseir

Sequence Model

• Steps

– Identify main tasks and express them as intents

– Identify trigger which sets off the sequence

– Add the steps to achieve the intent. Link use arrows, show loops and branches

– Review the steps , look for sub intent

– Identify breakdowns and problems

Week 5

by A.Nosseir

Artefact Model

• Steps

– Collect artefacts or images

– Check with customer that you understand the role of the artefact

– Annotate to highlight the relevant information

Week 5

by A.Nosseir

Figure 18.6 A model of a paper artefact.

7

Week 5

by A.Nosseir

Figure 18.7 Artefact model for an airline baggage label.

Week 5

by A.Nosseir

Cultural Model

• Components

– Influencers: whatever affect the way the work is done

– The extent the work has been affected

– The directions

– Breakdowns

Week 5

by A.Nosseir

Cultural Model

• Steps

– Start with a bubble for individual concern, add arrows with labels to show the influence

– Add outer arc to show the overall company culture

– Identify any breakdowns

Week 5

by A.Nosseir

Figure 18.9 A cultural model for the Swan Hotel.

8

Week 5

by A.Nosseir

Physical model

• Components

– The physical structure of the place

– Movements within the place –paths

– Communications, computer technologies and networks

– Locations of key artefacts (white board, desk)

– Layout of the workplace

– breakdowns

Week 5

by A.Nosseir

Figure 18.10 The physical model for the Swan Hotel.