case study

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Evidence-based Development in action

Applying Evidence-based Development in a large engineering project

Client: A UK defence Prime Contractor

Context

Our client is the lead contractor for a very large scale nuclear engineering development project for the UK MoD. Valued at more than £10Bn and with a time scale measured in decades, the project is also subject to an extremely stringent assurance and regulatory compliance regime.

Evidence-based Development (EbD) is integrate's approach to the through-life management of requirements and associated life-cycle information in complex systems projects. EbD delivers progressively increased confidence in the validity of development artefacts, providing a uniform approach to argumented verification and validation and producing assurance cases that are tightly coupled with system design.

What we did

The client has a well-developed corporate process for the capture and management of requirements. integrate was commissioned to implement and adapt this process for the particular needs of the project, including developing an appropriate information architecture that would support the assurance needs of the programme; introducing working-level processes and supporting software tools; supporting the roll-out to the project team; and training and mentoring users.

We began with an initial diagnostic phase aimed at understanding the project, its organisation and corporate process requirements and constraints. This was accomplished through a series of interviews and facilitated workshops. The information gathered was analysed, compared with cross-industry best practice elsewhere, and related to associated risks to the programme. This led to a series of risk-based recommendations which were accepted for implementation.

A key recommendation was that the client's existing process, which recognises the need to collect arguments and evidence for requirements decomposition, should be extended to include the collection of arguments and evidence related to verification and validation. V&V activities are considered as ‘requests for evidence’, and arguments for assurance are developed progressively from the early stages of V&V planning through to test fulfilment. This approach is a key concept behind Evidence-based Development, and allows for the progressive development of a well-argued assurance case that is tightly coupled to the system design.

To create a manageable and scalable process, we adopted an approach whereby the information architecture is organised into areas within layers (corresponding more-or-less to the product breakdown structure), and the same “micro-process” is applied to every area. This means that users find a familiar structure in whichever area they choose to work, and that exactly the same tool configuration is applied within each area.

During the implementation phase we:

  • Implemented in Rational DOORS® a layered information architecture, supporting the flow-down of requirements from business to component level and the collection of validation evidence and arguments at each life-cycle stage.
  • Developed processes and work-instructions for operating the "micro-process", applicable to all areas of the information model.
  • Configured software tools (including integrate's TraceLine for DOORS) to facilitate operating the "micro-process" in DOORS.
  • Found solutions to the problem of how to present complex, deep-dive traceability reports in graphical form for internal and customer technical review purposes.
  • Assisted with the rollout of the DOORS implementation and associated processes and tools to over 250 engineers across more than 20 departments.
  • Provided project-specific process training and at-desk mentoring to ensure effective uptake of the process and supporting tools.
  • Defined suitable progress metrics based on requirements and V&V development, and provided the means automatically to collect the data required.
  • Helped establish a tool-supported change management process compatible with the wider corporate change processes.

Outcome

The processes and tools introduced by integrate are in daily use by the project team, and integrate continues to provide occasional support and mentoring. The lessons-learned from the engagement are being considered by the client at corporate level, with a view to a wider roll-out of the processes and tools .

Evidence-based Development™ and EbD® are trade marks of Integrate Systems Engineering Ltd

Rational® and DOORS® are trademarks or registered trade marks of International Business Machines Corporation in the United States, other countries, or both.