This thesis surveys the field of software maintenance, and addresses the maintenance requirements of the Aerospace Industry, which is developing inige projects, running over many years, and sometimes safety critical in nature (e.g. ARIANE 5, HERMES, COLUMBUS). Some projects are collaborative between distributed European partners. The industry will have to cope in the near and far future with the maintenance of these products and it will be essential to improve the software maintenance process and the environments for maintenance. Cost effective software maintenance needs an efficient, high quality and homogeneous environment or Integrated Project Support Environment (IPSE). Most IPSE work has addressed software development, and lias not fully considered the requirements of software maintenance. The aim of this project is to draw up a set of priorities and requirements for a Maintenance IPSE. An IPSE, however can only support a software maintenance method. The first stage of this project is to deline 'software maintenance best practice' addressing the organisational, managerial and technical aspects, along with an evaluation of software maintenance tools for Aerospace systems. From this and an evaluation of current IPSEs, the requirements for a Software Maintenance Support Environment are presented for maintenance of Aerospace software
