Requirements Elicitation

Requirements Elicitation

1. Components

   • Application domain
   • Problems to be solved
   • Business context
   • Stakeholder needs and constraints

2. Elicitation, analysis and negotions

   • Drafting the statements
   • Analysing the requirements
   • The problems?
   • Negotiating
   • Making the document
   • Eliciting the requirements

3. Eliciting the Requirements

   • Establish the objectives
   • Understand the background
   • Organize Knowledge
   • Collect Requirements

4. Requirements Analysis

   • Necessity checking
   • Consistency and completness
   • Feasibility checking

5. Requirements Negotiation

   • Requirements agreement
   • Requirements prioritization
   • Requirements Discussion
   • Negotiation meetings

6. Elicitation techniques

   • Interviews
     • Closed inteviews
     • Open interviews
   • Scenarios
     • a description of the system state before entering the scenario
     • the normal flow of events in the scenario
     • exceptions to the normal flow of events
     • information about concurrent activities
     • a description of the system state at the end of the scenario
   • Soft system Methods
     • Is divided in stages
       • Problem situation assessment
       • Problem situation description
       • Abstract system definition from selected viewpoints
       • Conceptual system modelling
       • Model/real-world comparison
       • Change identification
       • Recommendations for action
   • Observations
   • Social analysis
     • Ethnography
       • Perspectives
         • The work setting viewpoint
         • Social and organisational perspectives
         • The workflow viewpoint
   • Requirements reuse
   • Problems
     • Not enough time
     • Inadequate preparations
     • Unconvinced of the need for new system

7. Prototyping

   • Prototyping benefits
     • User experimentation
     • feasibility and usefulness before high development costs are incurred
     • Customer understands look and feel
     • new study of requirements makes sure that nothing has been missed out
   • Types of prototyping
     • Throw away
       • intended to help elicit and develop the system requirements.
     • Evolutionary
       • intended to deliver a workable system quickly to the customer.
   • Costs and issues
     • Training
     • Development costs
     • Extended development schedules
     • Incompleteness
   • Approaches
     • Paper prototyping a paper mock-up of the system is developed and used for system experiments
     • Wizard of Oz’ prototyping a person simulates the responses of the system in response to some user inputs
     • Executable prototyping a fourth generation language or other rapid development environment is used to develop an executable prototype

8. Analysis Checklists

   • Premature design
   • Combined requirements
   • Unnecessary requirements?
   • Use of non-standard hardware

9. Interactions?

   • Make a matrix
     • For requirements which conflict, fill in a 1
     • For requirements which overlap, fill in a 1000
     • For requirements which are independent, fill in a 0