Automated Repair Service Bureau: Software tools and components

Complex software systems can be built from components, where a component is a software entity that performs one type of function in a general, usually table-driven, way. If the components are defined well and a standard interface is provided between them, the resulting product is flexible. It is easy to understand and easy to change. The performance of the system is a function of that of the components. The new Loop Maintenance Operations System Front End (LMOS-2) is a transaction processing system developed in this way. The components, described in this article, are a mask handler, a data validator, a database management system and a transaction-oriented filing system. Transactions are written in a high-level language designed for the purpose. The LMOS-2 system runs on the UNIX∗ operating system. The desired flexibility properties have been realized and have produced important benefits in the course of LMOS-2 development. Moreover, with considerable attention to the performance characteristics of the components, a system has been produced which is as fast and efficient as its predecessor, coded mostly in assembly language.