Automated Repair Service Bureau: Software Tools and Components

The software systems developed in the past for the Automated Repair Service Bureau (ARSB) have been well suited to the application. By almost any measure--performance, availability, protection of the database--they are excellent systems. Their major drawback is inflex- * UNIX is a trademark of Bell Laboratories. 1177 ibility--a fault shared with many systems of their generation, particularly production systems built for major applications. The Loop Maintenance Operations System (LMOS) front end (FE) was handcrafted for the ARSB application. The Bell Operating System (BOS) was built to the requirements of LMOS, as was the BOS Filing System (FS). The original application code was written in PDP* MACRO-11 assembly language. Application programs access and manage data files themselves, calling on FS only for direct operations on data blocks. As a result, database changes ripple through the application code, making change expensive and error prone. Another consequence of making LMOS very application-specific is that there has been little spin-off of LMOS technology to other projects. This is unfortunate, for LMOS has been an extremely successful product. During the past decade (but for practical purposes after the LMOS FE system was built and deployed), the UNIX operating system was developed, bringing with it new software development tools and new notions of software flexibility and transferability. 1 Several years ago, the UNIX operating system supplanted DEC's DOS operating system in our development environment and we began to write new programs in C.