Traceability James D. Palmer Presented by: Megan Heffernan
Agenda • What is traceability? • Why is traceability important? • How is traceability performed? • What tools perform traceability? • What is the future of traceability?
Introduction • What makes a software project successful? • Meets stakeholder requirements • How can this be encouraged? • Traceability • Traceability in a nutshell • Shows forward and backward relationships linking requirements with design, implementation, test, and maintenance • Know reasoning for everything and how to test
Why is Traceability Important? • Ensures that requirements are met • Understand relationship between requirements and the delivered system • Lowers risk • Creates an audit trail • Consistency • Control • Change • Development • Risk
Problems with Traceability • Manual process • Viewed by developers as a low priority • Misunderstood • No single modeling method • Poor documentation
When Does Traceability Occur? • Entire lifecycle!
How is Tracing Performed? • Client gives developers rough requirements • Developers create system, hardware, and software requirements • Each element is given a unique identifier • Element – requirement, design attribute, test, etc • Linkages done manually and managed by a CASE tool • Traceability tables are made • Matrix
Traceability Example • SRD – System Requirements Document • High level requirements • Done by stakeholders • SS – System Specification • More detailed requirements • Developer interpretation • Segments • More detailed portions of the SS • Includes design information
Traceability Example System Requirements Document System Specification Interface Control Document Segment 2 Segment 1 Segment 3
Traceability Example Traceability Matrix
Traceability Management • Requirements are added/deleted/modified • Impact analysis • Trace changed • Continues through maintenance
Traceability in a Perfect World • Steps • Identification of requirements • Architecture selection • Classification schema • Functions, Performance and Security • Translate into views • Allocation into schemas • Flow-down to design, code, and test • Entry into traceability database • Linkages • Management
Traceability in the Real World • Labor Intensive • Classification schemas are frequently changed as requirements are allocated • Ensure that semantics and syntax are correct
Semantics and Syntax • Semantics required to assure that a trace is used in context • Syntax required to assure that a trace goes to a specific word or phrase • Manual verification of outcomes
Real World Traceability Workflow • Receipt of requirements documents • Select architecture form to be followed • Select classification schema • Parse document and assign unique numbers • Allocate according to classification scheme • Establish linkages across all requirements • Generate traceability matrices • Maintain traceability linkages in database • Maintain traceability links across entire project
Return on Investment • Very difficult to measure • Many factors • Costs • Time • CASE Tools • Training • Benefits • ??? • Only an estimation • What rework was avoided?
Tools • CASE Tools • Characteristics • Hypertext linking • Unique identifiers • Syntactical similarity coefficients • Problems • Hypertext linking and syntactical similarity does not consider context • Unique identifiers do not show requirement information • Choosing architecture view and classification schemas will always be manual
Tools • DOORS • Telelogic • “capture, link, trace, and manage” • For large applications • From the datasheet • Similar look and feel to explorer • Gap analysis for unaddressed requirements • Traceability analysis for identifying areas of risk • Impact analysis reports • Volatility • Traceability by drag and drop
Tools • Caliber-RM • Borland • From the datasheet • Centralized repository • Requirements traceability across the lifecycle • Impact analysis
Future Predictions • Automation of allocation into architectures and classification schemas • Little additional automation seen in current tools • AIRES (Automated Integrated Requirements Engineering System) • Center for Software Systems Engineering at George Mason University • Relies heavily of semantics and syntax
Pros/Cons • Pros • Clearly reflected traceability importance and need • Practical workflow • Cons • Examples did not reflect lifecycle • Little practicality with tools
Agenda Revisited • What is traceability? • Why is traceability important? • How is traceability performed? • What tools perform traceability? • What is the future of traceability?