Software Development for the Zodiac Tactical Switch

The approaches used for the development and management of the ZODIAC Switch software package, a large microprocessor-based program, were adopted by GTE in order to guarantee a reliable, well tested, and easily modifiable program. Since more than 60 percent of the development costs for the ZODIAC Switch project were for software, techniques needed to be adopted that would lower the risk of any cost or schedule problems. This paper addresses some of the techniques, documentation, and tools used to lower this risk and analyzes the final results including what we might have done differently.