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Traceability

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Used in existing powerfull RT tools (RTM use runtime version of Oracle) Regular expressions ... Object based (see RTM tool too) Declaration using FOOP (based on OBJ) ... – PowerPoint PPT presentation

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Title: Traceability


1
Traceability
Systems Engineering STD
Requirements Management2 Traceability
2
Contents
  • Terminologies
  • Techniques
  • A model of traceability
  • Tools case study
  • (RTM, Slate, DOORS what will be available at
    HPI !!)

3
What specific to Traceability in Req. Management ?
  • Traceability increase software quality throughout
    the life of the project
  • Most important issue in RM
  • Many facets of Soft.Eng. Can be improved through
    RT
  • Standard 2167A (US DoD)

4
A recent event Mad cow and Hamburger !!
?
5
Terminologies
  • Part of requirement management process
  • Technique to provide relationship between
    requirement design and final implementation
  • How and why system development products satisfy
    stakeholders requirements
  • Ability to discover the history of every feature
    of a system
  • A quality factor
  • Many standards (2167-A then 498) require the
    development of traceability documents

6
Techniques
  • Objectif get all links during lifecycle of
    requirement
  • Link to stakeholders
  • Associated design
  • Associated implementation
  • Validation procedure
  • Concept of operation
  • Etc ...

7
Techniques
  • Cross reference schemes
  • Keyphrase dependancy
  • Templates
  • Matrices
  • Matrix sequence
  • Hypertext
  • Integration documents
  • All differs in the intent of information
  • traced and objective of tracing

8
Essence of traceability
  • Of What (information)
  • In what way (information prsentation)
  • For whom
  • Example Who coded the program
  • Who we need the programmer
  • What way name, the company, the team ?
  • For whom to whom this information is addressed
  • (not anybody can have any information
  • information abstraction and ... Security)

9
Traceability Matrix
  • Used to relate requirements to others software
    developments artifacts

The relation can be allocatted a type
Design Di
S/w modules
Req
R1
R2
X
Rn
N/A
X relational link between a requirement and a
design N/A Non applicable (no apparent link)
10
Cross references and index schemes
  • References made across several items (design,
    modules, requirements,..) in order to link two
    items or artifacts.
  • Example There should be a high-level of
    traceability between "Logical Architecture" and
    "Physical Architecture"
  • The logical and physical architecture are tied
    together with a collection of cross-reference
    tables in the "Traceability Matrix"

11
Tracing languages
  • Database query languages
  • Used in existing powerfull RT tools (RTM use
    runtime version of Oracle)
  • Regular expressions
  • Used in formal TOOR approach
  • TOOR
  • is designed for tracing requirements in system
    development.
  • It considers as objects, in the computing science
    sense of the word, any artifacts used during the
    development of a software system, e.g., an
    interview transcript, a video tape, a design
    chart, a program specification text, a system
    manual, etc.
  • It also considers the possible relations between
    any two objects as an object itself

12
Tracing Process and models
  • Trace definition precise semantic (formalising
    links between objects)
  • Trace production results of action (ideally
    automated tracing production)
  • Trace model link between classes dont give
    exact purpose of the link
  • Trace extraction What are the requirement that
    are linked to a specific software or what are
    the software modules linked to a specific
    requirement
  • Traceability support A huge amount of
    information to manage

13
TOOR . A formal approach
  • Developped at Oxford (Goguen, Pinheiro)
  • Object based (see RTM tool too)
  • Declaration using FOOP (based on OBJ)
  • Traceability links between any artifacts created
    by different documents
  • Graphical interface
  • Tracing are forward and backward

14
TOOLS RTM
  • Requirements Traceability Module (Chipware)
  • Other tools DOORS (telelogic), Slate (QSS)
  • Essential approach
  • A generic meta model
  • All links are specified in the relation between
    between classes
  • Document generation
  • Can be customised to any meta-model defined by
    user

15
A model of traceability
16
A model of traceability
Separation between source and other objects
  • A manager
  • A user
  • A programmer
  • -Email
  • Doc
  • phone call
  • Meeting minutes
  • A Requirement
  • A Designed architecture
  • A software module

17
A model of traceability
18
Dependancy links issues
  • Existence of a link and its meaning
  • Stakeholders dependencies
  • Requirements dependancies a requirement is
    based on the assumption on satisfaction of
    another requirements the software can be coded
    in C only if here is available compiler on
    operating systems imposed in another requirement
  • Task dependencies
  • Resource dependancies
  • Temporal dependancies (temporal order)

19
Relative importance of dependancy links
  • Attribution of weight on on link
  • Qualitative
  • Quantitative
  • Example The voltage change in one component
    affect another component
  • Links can be many levels of abstraction
  • Requirement and derived rtequirement
  • Requirement and stackholder
  • Not injective or surjective relation

20
Conclusions
  • A model of traceability should be defined
  • A need for a tool
  • Two way to implement the tool
  • Specific tool for RT
  • A database system as Oracle.

21
Conclusions and recommendations
  • State of the art and limitations
  • All approaches require a great deal of manual
    effort to define the links
  • All rely on purely syntactic information with no
    semantic or context
  • capture situations where many people participate
  • Capture changing patterns of participants

22
Conclusions and recommendations
  • Informational problem
  • Tracking useful information
  • Inadequate prerequirement traceability
  • Informal communication
  • People attach great importance to personal
    contact and informal communication
  • These always supplement what is recorded in
    database
  • Traceability links database tells only a part of
    the story
  • Finding the appropriate people

23
Conclusions and recommendations
  • Involvement
  • ?Who has been involved in the production of a
    requirement and how
  • Responsibility
  • Who is responsible for a specific requirement
  • Who is currently responsible
  • Context in defining change of responsibility
  • Change
  • At what point in the life of a requirement a need
    for a change is possible
  • Who needs to be informed by a change

24
Conclusions and recommendations
  • Loss of a knowledge
  • ? What are the items regarding the loss of a
    project knowledge due to turnover over concerned
    personnel
  • Others
  • Verification and validation
  • Maintenance
  • Coverage (types of links)

25
Next lecture
Requirements management Traceability
Validation and Verification
26
Paper Reading and assignments
  • Paper reading
  • Mandatory Traceability IEEE Trans jan 2001 by
    Jark Ramesh
  • Other see list paper reading assignment
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