COMPLEMENT was a thirty-month project funded by the European Community under the ESPRIT programme (Project 5409), to study methods and tools for practical use in the development of real-time and embedded systems. (The project name was derived from COMPrehensive Large-scale Engineering MEthodologies aNd Technology transfer.) Over 100 people from 19 industrial and academic organizations participated, during the period from October 1990 to April 1993. The work of the first half of the project was reported in the book Real-time Systems: Investigating Industrial Practice (Pyle et al 1993). Performance was one of the issues considered in the project, but little progress was made in the first period, other than identifying the problem and planning how to address it. Individual working papers of the project were prepared during the rest of the project, but they have not been coordinated or published coherently. The principal industrial and academic partners involved in this work have used the project, as intended by the CEC, in their own activities. The paper reports the author's understanding of the situation reached in COMPLEMENT, based on these working papers and subsequent association with one of the partners involved.