Performance engineering is a fast-moving field where advances in technology mean that new issues constantly need to be addressed. In response to this, the UK Computer and Telecommunications Performance Engineering workshops were set up in 1985 to provide a valuable opportunity for the discussion and exchange of ideas. They have subsequently become well established as the focus for academic and industrial practitioners from the UK and Europe with an interest in performance and modelling and analysis. This volume contains the 16 papers which were presented at the 7th annual workshop, held in Edinburgh in July 1991. The workshop highlighted various aspects of parallel computing - an area which is attracting an increasing amount of interest - and the work presented in these papers is of particular interest as the contributors used real analysis to evaluate their models. The papers cover a wide range of topics, both practical and theoretical, including advances in queueing theory, common performance problems and their solutions, assessments of available tools and presentations of new theoretical results.