In reply to David Perry:

Whilst it's best to have clear job descriptions, I've always been an advocate, coming from a project engineering background, of job-grading / promoting staff such as engineering designers or design engineers very flexibly and without a lot of rigmarole or particular justification, according to the highest level of responsibility they're deemed to be capable of working-at - don't forget it was *project* engineering, so project teams changed and changed again depending on the particular project(s) in hand. That way, job holders don't need to have to wait for higher-graded jobs to become available - once they prove themselves capable of working at a higher level, they're offered promotion. It follows that the actual project team / management structure is not fixed or rigid but is in a constant state of change - and that, especially when workloads are diminished, some high-grade staff might well temporarily be working on jobs that don't at all stretch their capabilities.

Of course all this may not work eg in the case of staff who move to particular vacancies that may arise in different functions to their own - eg design engineers become site or project managers or project planners or engineering buyers but for staff within the same job role I've found that this approach can work very well indeed.