The difficulties encountered during development of the Theater Battle Management Core System (TBMCS) provide lessons for systems engineering of large-scale, software-intensive systems. The absence of formal requirements and oversight, coupled with strong pressure for rapid deployment, caused the program to fail its first operational tests and actually delayed its deployment to the field.
The lack of measurable requirements and the need to integrate multiple third-party products and systems made it impossible to establish a system baseline and to test TBMCS in realistic conditions. Thus, significant problems manifested themselves only
during official government tests. Moreover, despite nominal authority, the lead contractor had little or no control over the government-furnished elements and commercial off-the-shelf products that TBMCS was to incorporate.
Experience with TBMCS leads to several conclusions. First, the more complex a system, the greater the need for rigor and discipline in engineering processes. Second, well-defined requirements are essential. Third, mandating the incorporation of specific thirdparty
hardware or software may create severe problems for system development. Other lessons highlight the importance of open standards in a heterogeneous information technology environment and of layering with well-defined interfaces to facilitate integration and system evolution.