The challenge is underscored by the staggering growth of software as a part of the overall weapon systems acquisition enterprise. Over a five year period, the planned subsystem development for a critical weapons program ballooned from 4 subsystems to 56, and the number of lines of code from a half a million to nearly a million and a half. Software modifications for a representative aircraft system is approximately one million lines-of-code per year. Large scale networked battlefield systems are connected by apporximately 33 million lines of software code. Today, software maintenance costs account for somewhere between 50% and 80% of the overall software life cycle costs.

In the face of such trends, a well-designed software sustainment strategy is particularly critical to future force operations. Yet, decision-makers today have very limited analysis and decision support capability to identify and make effective tradeoff decisions.

The PDSM Technology

PDSM begins when any portion of the production quantity has been fielded for operational use. Typical software maintenance may involve adding new functions or capabilities, deleting obsolete capabilities, modifying software to address a change in the environment or to better interface with other systems, and performing the periodic tasks needed to keep software operational after it is deployed. Less often considered, PDSM includes the assessment, execution and oversight of performance based logistics initiatives.

KBSI's goal in the PDSM effort is to develop an advanced methodology and supporting tools to facilitate the definition of post-deployment software support staff selection, staffing levels, and training requirements for emerging weapons systems. In meeting this goal, KBSI will utilize PROSIM® to model and study the system under dynamic conditions, and from this data, forecast resource utilization and performance characteristics, determine time-varying cost behavior, and help discover parametric relationships. KBSI's SMARTCOST® tool will be used to capture the system's parametric relationships, which quantify one or more characteristics of a product or service in terms of other characteristics, to develop cost estimates or estimates of other quantiative metrics of interest.

The PDSM technology will help analysts determine the post-deployment software operations and maintenance burden and the key factors affecting overall operations and maintenance workload. In addition, the PDSM technology provides the foundation for quantifying the effects of changes in maintenance concepts and doctrine, changes in the external environment, changes in maintenance-related process design, and variations in human performance to gauge their effects on both maintenance and operational unit performance (e.g., go-to-war capability and availability).