OPTIMUM-AIV: A planning and scheduling system for spacecraft AIV

This paper presents a project undertaken for the European Space Agency (ESA). The project is developing a knowledge-based software system for planning and scheduling of activities for spacecraft assembly, integration, and verification (AIV). The system extends into the monitoring of plan execution and the plan repair phases. The objectives of the contract are to develop an operational kernel of a planning, scheduling and plan repair tool, called OPTIMUM-AIV, and to provide facilities thatwill allow individual projects to customize the kernel to suit its specific needs. The kernel shall consist of a set of software functionalities for assistance in initial specification of the AIV plan, in verification and generation of valid plans and schedules for the AIV activities, and in interactive monitoring and execution problem recovery for the detailed AIV plans. Embedded in OPTIMUM-AIV are external interfaces that allow integration with alternative scheduling systems and project databases. The current status of the OPTIMUM-AIV project, as of January 1991, is that a further analysis of the AIV domain has taken place through interviews with satellite AIV experts. A software requirements document (SRD) for the full operational tool has been approved and an architectural design document (ADD) for the kernel, excluding external interfaces, are ready for review. At the time of the conference, the implementation will be well underway expecting a final delivery in September of 1991. 1. I N T R O D U C T I O N The size and complexity of the tasks involved in the assembly, integration, and verification (AIV) of spacecraft raises the need for efficient and flexible planning and scheduling tools. An evaluation of the current available and applied commercial tools reveals their inadequacies towards the general problem o f AIV. In 1988 this led European Space Agency (ESA) to award a contract to a consort ium consisting of CRI, M A T R A ESPACE, and AIAI , which should assess the applicability of Artificial Intelligence (AI) and knowledge based system (KBS) techniques in a M. M. Arentoft is a research engineer, MSE-EE & MSE-CS, and Project Manager of the OPTIMUM-AIV project, .Computer Resources International, Bregnerodvej 144DK-3460, Birkerod, Denmark. Y. Parrod is a research engineer with MATRA. J. Stader is a research scientist with AIAI. I. Stokes is Department Manager with Progespace, tI. Vadon is Technical Project Officer for ESA/ESTEC.