Lecture Requirement engineering Chapter 7 Requirement management

Lecture Requirement engineering Chapter 7 Requirement management. This chapter presents the following content Requirement management, requirements change factors, traceability, traceability across the life cycle,...

Requirement Management

Requirement Management is a process to

all requirements are satisfactorily

implemented and accepted

 Proposing

changes

 Analyzing impact

 Making decisions

 Updating

requirements

documents

 Updates plans

 Measuring

requirements

volatility

 Defining a version identification

scheme

 Identifying requirements document versions

 Identifying individual requirement versions

 Defining a possible requirement statuses

 Recording the status of each requirement

 Reporting the status distribution

of all requirements

 Defining links to other

requirements

 Defining links to other system elements

Change control Version control Requirements

status tracking

Requirements tracing Requirements

Management

Requirements errors, conflicts, and

inconsistencies

May be detected at any phase (when requirements are analyzed, specified, validated, or implemented)

Evolving customer/user knowledge of the

system

When the requirements are developed,

customers/users simultaneously develop a better understanding of what they really need

Technical, schedule, or cost problems

Difficult to plan and know everything in advance

We may have to revisit the list of requirements and adapt it to the current situation

Changing customer priorities, new needs

Requirements traceability refers to the ability

to describe and follow the life of a

requirement

Traceability

Provide a traceability analysis or matrix which links requirements, design specifications, and

validation

Providing the links necessary for determining

where information is located

Traceability

It demonstrates the relationship between design inputs and design outputs

It ensures that design is based on predecessor, established requirements

It helps ensure that design specifications are appropriately verified, that functional

requirements are appropriately validated

Traceability

Requirement Depends-on

Risk Assessment (Initial and Ongoing

Activities)

Trace potential risks to their specific cause

Trace identified mitigations to the risk

Trace specific causes of software-related risk to their location in the software

Requirements Analysis and Specification

Trace Software Requirements to User

Requirements

Trace Child Requirements to their Parent

Requirement

Trace Software Requirements to hardware, user, operator and software interface requirements

Design

Trace Architectural Design to Software

Requirements

Trace Design Interfaces to hardware, user, operator and software interface requirements

Trace Detailed Design to Architectural Design

Source Code Analysis

Trace Source Code to Detailed Design

Specifications

Trace unit tests to Source Code and to Design Specifications

Integration Test

 Trace integration tests to Architectural Design

System Test

 Trace system tests to Software Requirement

Specifications

 Use a variety of test types

 Design test cases to address concerns such as

robustness, stress, security,

 recovery, usability, etc

 Use traceability to assure that the necessary level of coverage is achieved

The requirements baseline is the set of

functional and nonfunctional requirements

that the development team has committed to implement in a specific release

At the time the requirements are baseline – typically following formal review and approval – they are placed under configuration

management

During project planning, a PM decides which process is to be followed for handling change requests

Because change requests have cost

implications, it is necessary to have a clear

agreement

Some requirements problem is identified

Could come from an analysis of the requirements, new customer needs, or operational problems with the system

Log the changes in CR form

The proposed changes are analysed

Perform an impact analysis on the work products

Estimate the effort needed for the change

requests

Re-estimate the delivery schedule

Perform a cumulative cost impact analysis

Review the impact with senior management if

thresholds are exceeded

Obtain customer sign-off

The change is implemented:

Rework work products through its life cycle