Last week the UK chapter of INCOSE (International Council on Systems Engineering) held their annual systems engineering conference on the Warwick University campus. I'd like to share some of what I heard during the conference, both on systems engineering in general, and more specifically on requirements management practices in the systems engineering domain.
One of the keynote speakers was Dr Sandy Wilson, President & Managing Director, General Dynamics UK. Dr Wilson spoke about the key challenges in the defense industry - the rate of change in threats and technology and the need to lower costs. He challenged the V model - said it's a nice diagram but its linearity is an issue - the world is not linear or rigid but the SE V diagram is. He spoke about the need for the defense industry to become more agile but that today change is cumbersome due to contractual issues and governance constraints. There are two main types of defense procurement done in the UK - the longer term needs are met by EPs (Equipment Programmes) and the urgent tactical needs by UORs (Urgent Operational Requirements). The former is bogged down in top level scrutiny and check boxes. The latter is helped by the top level sense of urgency and support. An example of a UOR was the decision to implement the multinational no-fly zone over Libya. Dr Wilson proposed that all defense projects should become more like UORs - more agile. He said that "an 80% solution delivered 1 year earlier is better than 90% delivered 4 years late". I heard that delivering incremental capability needs asset management and tracking, configuration management and a more agile approach to systems engineering - valuing "Product over Process". As well as changes in the way companies deliver capabilities, a change is needed in the way the customer (governments) do their acquisition and contracts in order to enable more agility.
Dr Jeremy Dick of Integrate Systems Engineering
and co-author of the book 'Requirements Engineering' presented a case study in the aerospace industry on developing the assurance case for a (safety) critical system in parallel with requirements analysis, design, verification & validation, using an extension of his technique for documenting the rationale for traceability relationships known as 'rich traceability'. In addition to developing a requirements 'flow-down' (through levels of requirements to design), the 'evidence' supporting the flow-down is documented. The evidence in the early stages can be how you expect the lower level requirements or design elements to satisfy the higher level and your evidence to suggest that your argument is sound. In parallel your verification & validation strategies should be evolved, including an argument and supporting evidence for how the test(s) will prove the requirement(s) is/are met. Jeremy was asked how the textual requirements, arguments and evidence would fit with a MBSE (Model-Based Systems Engineering) approach. Jeremy answered that he favours (and in fact came up with the concept of - ref: "The Systems Engineering Sandwich: Combining Requirements, Models and Design", Jeremy Dick, Jonathon Chard, INCOSE International Symposium, Toulouse, July 2004) the sandwich model - interleaved layers of requirements and modeling used to decompose a system specification adn design (you can read more on that concept in the post 'Food for thought: The Systems Engineering Club Sandwich'
Chris Rolison, CEO, Comply Serve
, continued the theme of progressive assurance with focus on the rail industry. Chris highlighted the complexity challenges in major rail infrastructure projects, and the issues presented by paper-based systems, silos in organization structures, and the supply chain. Chris said that "up to 80% of the engineering requirements can change during design & build" - not because the customer changes their mind but because of all the external factors involved in building a rail system. Chris went onto describe a more collaborative, requirements-driven design approach where systems engineering principles are applied, supported by a collaborative platform (ComplyPro which is based on IBM Rational DOORS).
Alastair Mavin of Rolls Royce 'lent' us his EARS (Easy Approach to Requirements Syntax
(link is to an IEEE publication - sign in required) an application of a template with an underlying rule set on how to describe requirements using natural language but in a more structured, consistent way. He described the latest version of the template EARS+ (or as he nicknamed it 'Big EARS' !) and the benefits of the approach - simplicity and structure combined.
I could go on for pages about all of the great content shared at this excellent event but I'll leave it there with the main requirements related topics, except to quote from the keynote speaker on day 2: "The core of Systems Engineering is defining requirements and delivering against them". I'd put it this way - you can't have successful systems engineering without effective requirements management.