Requirements engineering vii

RequirementsEngineering

Indri Sudanawati Rozas

Juni 2012

Activities?

Feasibilitystudy

Requirementselicitation and

analysisRequirementsspecification

Requirementsvalidation

Feasibilityreport

Systemmodels

User and systemrequirements

Requirementsdocument

Requirements Management

Success Starts

with

Requirements Management

Software Crisis

• CHAOS report indicates only a distinct minority of software projects is completed on time and under budget– Successful projects are only 16.2%– Challenged projects accounted for

52.7%– Impaired projects accounted for 31.1%

Causes of Software Crisis

• Failures attributed to poor requirements management– Incorrect definition of requirements– Poor management throughout

development lifecycle

Solution to Software Crisis

• Effective requirements management! – The factor most related to successful

projects– Ensures right problem is solved– Ensures right system is built

Requirements Management

• A systematic approach to– Eliciting– Organizing– Documenting– And managing the changing requirements of a software project

• Not a new concept!

Rational Approach to Requirements Management

• Rational provides complete solution to requirements management– Rational Unified Process(RUP)

• Recommends specific requirements management skills

• Provides specific guidelines to effectively implement skills

– Tools to automate these skills • RequisitePro, Rose, ClearCase

Requirements Management Skills

• Six essential management skills:– Analyze the problem.– Understand the user needs.– Define the system.– Manage the scope of the system.– Refine the system definition– Manage the changing requirements

Requirements Management in RUP

• Requirements management skills implemented in the requirements core-workflow

• Considered workflows

Analyze the Problem

• Purpose is to:– Gain an agreement on system features and

goals– Develop Vision document for the project

• The key artifacts produced in the workflow:– Vision document– Requirement management plan for the

project– Glossary

Understand the User Needs

• Purpose is to:– Collect information from the various

stakeholders of the project– Use different elicitation techniques to

elicit requests

Understand the User Needs

• The key artifacts produced in the workflow:– Refined vision document– Initial Use case model– Supplementary specifications– Refined glossary

Define the System

• Purpose is to:– Ensure that all project team members

understand the system– Perform high-level analysis on the results

collected in previous workflows– Formally document results

Define the System

• The key artifacts produced in the workflow:– Refined vision document– Refined use case model– Refined Supplementary specifications– Refined glossary

Manage the Scope of the System

• Purpose is to:– Define the set of requirements to be

included in this version of the system– Define a set of architecturally-significant

features and uses cases– Define attributes and traceability to help

prioritize requirements

Manage the Scope of the System

• The key artifacts produced in the workflow:– Iteration plan– Refined vision document– Refined glossary

Refine the System

• Purpose is to:– Provide a more in-depth understanding

of the system’s features – Provide detailed descriptions of use

cases– Model and prototype user interfaces

Refine the System

• The key artifacts produced in the workflow:– User-interface prototype– Detailed use case model– Revised iteration plan– Refined vision– Refined glossary

Manage Changing Requirements

• Purpose is to:– Control and manage change– Set up appropriate requirements

attributes and traceabilities

Tool Support - RequisitePro

• Easy to use requirements management tool

• Leverages the power of database with the freedom of Word

• Multi-user support• Provides distributed access to projects via

its Web interface• Provides document templates and

capability to import existing documents

RequisitePro Manages Requirements

• Define System – templates, import capability, requirement and document types

• Manage scope – Traceability matrix and tree, attribute types

• Manage change – Suspect links, group discussions, revision history

Why Manage Requirements?

• Meeting the project’s requirements defines success!

Why Rational Approach?

• Rational provides a more disciplined approach to requirements management.– Does not only tell organizations what to

do, provides assistance on how to do it

• Rational dedicated the last few years to requirements management

References

• 1. Davis, Alan, Leffingwell, Dean. Using Requirements Management to Speed Delivery of Higher Quality Applications. Rational Web Site. On-line at http://www.rational.com/products/whitepapers.

• 2.  Kruchten, Philippe. The Rational Unified Process: An Introduction, Second Edition. Reading MA: Addison Wesley Longman, October 2000, pp.155-169.

• 3. Leffingwell, Dean. A Field Guide to Effective Requirements Management under SEI’s Capability Maturity Model. Rational Web Site. On-line at http://www.rational.com/products/whitepapers.

References

• 4. Leffingwell, Dean. Managing Software Requirements: A Unified Approach. Reading MA: Addison Wesley Longman, November 2000.

• 5. Oberg, Roger. Applying Requirements with Use Cases. Rational Web Site. On-line at http://www.rational.com/products/whitepapers.

• 6.  Parackel, Thomas. Managing Requirements in a Development Cycle. IWD Web Site. On-line at http://www.indiawebdevelopers.com/articles.

• 7. Rational RequisitePro. Rational Web Site. On-line at http://www.rational.com/products/reqpro.

• 8.  Royce, Walker. Software Project Management: A Unified Framework. Reading MA: Addison Wesley Longman, December 1999, pp.118-124.