Tracing
description
Transcript of Tracing
Tracing
CS4310
Fall 2012
What is Requirements Traceability?
• The ability to describe and follow the life of a requirement throughout the system lifecycle, in both forward and backward directions.
DoD Std 21267A• The document in question contains or implements all
applicable stipulations of the predecessor document• A given term, acronym, or abbreviation means the
same thing in all documents• A given item or concept is referred to by the same
name or description in the documents• All material in the successor document has its basis in
the predecessor document, that is no untraceable material has been introduced
• The two documents do not contradict one another
Artifacts• Pairs: What artifacts can be used for
tracing, 3 minutes. Think of the following stages:
• Elicitation
• Specification
• Construction
Artifacts• Elicitation
– Interview report– Requirement specification– Memos, conversations, email
• Specification– SRS
• Construction– Design models– Code– Test plan
Tracing
• An SRS is traceable if it is written to facilitate referencing individual requirements.
Tracing
• An SRS is traceable if it is written to facilitate referencing individual requirements.
• Take some feature of design and map it through the SRS to the source of the requirement.
Tracing
• An SRS is traceable if it is written to facilitate referencing individual requirements.
• Take some feature of design and map it through the SRS to the source of the requirement.
• How: careful and complete numbering of the sections and elements of the SRS.
Tracing
• An SRS is traceable if it is written to facilitate referencing individual requirements.
• Take some feature of design and map it through the SRS to the source of the requirement.
• How: careful and complete numbering of the sections and elements of the SRS.
• An SRS is traced if a flow up path can be identified between a requirement in the SRS and system level requirements in a statement of need or some other artifact (email, meeting notes, etc).
Tracing
• For any feature of the deliverable,
– Trace to its initial source
– Trace to its ultimate implementation
Types of tracing
• Pairs: Name four types of tracing
Types of tracing
• A. Forward from requirements
• B. Backward to requirements
• C. Forward to requirements
• D. Backward from requirements
1. 2.
3. 4.SRS
C. A.
D. B.ELICITATIONARTIFACTS
CONSTRUCTIONARTIFACTS
Benefits• V&V
• Align business needs with software being developed
• Reduce risk by capturing knowledge vital to project success
• Determine impact of change to requirements
• Support process improvement
• Conflict detection and resolution
Tracing helps QA/QC
• everything must be verified
• goals of verification– results may not be binary– verification may be objective or subjective
When?
• Continuously.– Initially
• Interview, prototype
– Elaboration• Architecture
– Construction• Unit testing, verification
– Maintenance
Secrets
• Trace continuously
• Understand why traceability is important
• Have a strategy
Problems
• It’s hard to do: manual links
• Benefits frequently not seen until later
• Difficult to measure return on investment
Requirements Management
• Requirements management is the set of activities that help the project team to identify, control, and track requirements and changes to requirements at any time as the project proceeds.
• Requirements management begins with the identification of requirements.
Requirements Management- Identification
• Each requirement is assigned a unique identify that might take the form:– <artifact-identifier><internal-identifier>
• artifact-identifier: code that identifies the artifact.– e.g., FR for Feasibility Report, SRS for Software
Requirements Specification, IR for Interview Report, M11-10-03 for Memoranda dated 11/10/2005.
• internal-identifier: code that references a section, a requirements number, or some other part of the document. – The internal identifier should allow someone to locate the
information easily.
Traceability Tables
• Possible types of traceability tables include:– Features traceability table
– Source traceability table
– Dependency traceability table
– Subsystem traceability table
– Interface traceability table
Traceability Tables
• Features traceability table: - Shows how requirements relate to important
customer observable system/product features.
• Source traceability table: - Identifies the source of each requirement.
• Dependency traceability table: - Indicates how requirements are related to one
another.
Traceability Tables
• Subsystem traceability table: - Categorizes requirements by the
subsystem(s) that they govern.
• Interface traceability table: - Shows how requirements related to both
internal and external system interfaces.
Source Traceability
SRS Requirements
IR Proto Memo 1 … … Artifact n
req1
req2 x x
…
x x
x
x
… x x x
reqn x
Sources