PTL personnel have extensive experience of high integrity software development and have contributed to the definition of standards in both the safety critical and security critical software fields. This experience includes co-authorship of Issue 2 of Def Stan 00-55 and review contribution to standards such as IEC 61508, Def Stan 00-56, Def Stan 00-55 Issue 3 and DO-178B/C. Our software development and consultancy experience ranges from real time embedded software of the highest levels of criticality through to information systems and computer simulations at lower levels of integrity. PTL is therefore well qualified to provide a complete range of services on high integrity software, including the following:

A good software quality process is at the heart of every effective high integrity software development process. PTL personnel have developed software quality systems that have been successfully assessed against these requirements of ISO 9001 and TickIT. We provide a service to develop software quality systems or to advise on the suitability of existing software quality systems, either for TickITplus certification, or as a basis for a high integrity software development

Whilst TickIT compliance is likely to be necessary for development of high integrity software, it is unlikely to be sufficient. Depending on the required level of integrity of the software, more rigorous techniques are likely to be required, supported by appropriate tools. We provide a service to assist companies in setting up the appropriate infrastructure to produce high integrity software, including advising on techniques and tools and the definition of procedures defining processes that meet the relevant safety software development standard.

We provide services to design and develop small real time embedded systems, primarily where high quality development is required such as for safety applications. Alternatively we have separately conducted individual key aspects of development, in particular the definition of requirement specifications and the establishment of a basis for traceability matrices to demonstrate the implementation and verification of all of the requirements.

In addition to the more complete safety assessment activities, we also provide auditing and review services. These audits and reviews are aimed at providing a 'health check' of particular aspects of a system or software development to confirm their adequacy or identify any weaknesses.

We have extensive experience of static analysis tools and techniques, as well as dynamic testing and issues associated with test coverage. We are able to either conduct Independent Verification and Validation on behalf of a client or advise and set up a V&V system appropriate for the required level of integrity.

We conduct studies on particular aspects of high integrity software development, for example to derive requirements for situations that are not explicitly covered under existing standards. Such situations could include software reuse, especially where the original software was not developed to safety standards, or the use of information systems to make potentially safety related decisions.