PhD ThesisFor an engineer to be able to modify successfully a complex computer-based
system, he will need to understand the system's functionality. Traceability can
help the engineer to gain that understanding, but several surveys have observed
that traceability information is poorly recorded. This thesis argues, based on a
survey of nine aerospace projects, that one of the main causes of poor recording is
that Traceability does not directly benefit the development process. The recording
of traceability information is best performed by the engineers directly involved in
the development process, yet it is precisely these engineers who seem to obtain no
direct benefit in performing this task. This can be summarised as the Traceability
Benefit Problem. To overcome this problem the recording of traceability data
must provide immediate, tangible benefits to the engineers involved in the current
development process.
A related problem that occurs in large multi-team projects that follow
development processes based on predictive models (such as Waterfall or VModel)
is the changing of interface documentation without adequate negotiation
(referred to as Throwing the Problem over the Wall). This thesis describes, in
detail, how a small automotive sensor project addressed these problems by
developing a Requirements Traceability system that enabled the reuse of software
and provided a basis for the negotiation of changes with their customer. Analysis
of the lessons learnt from the automotive sensor and aerospace projects lead to the
definition of the Traceable Development Contract.
The contribution of this thesis is the description and discussion of the Traceable
Development Contract, a method of coordinating the interaction of related
development teams in development process that is based on a predictive
development model. The Traceable Development Contract is proposed as a means
of controlling the upstream team bias with respect to the imposition of changes,
by employing traceability to provide a basis for the negotiation of change. By
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employing traceability in this way, it becomes beneficial to the development
engineers and therefore overcomes the Traceability Benefit Problem.
Finally, the thesis considers how the Traceable Development Contract traceability
information can be exploited further to provide solution maturity and design
metrics
