IMPACT OF HARDWARE OBSOLESCENCE ON SYSTEM SOFTWARE FOR SUSTAINMENT-DOMINATED ELECTRONIC SYSTEMS
Sandborn, Peter A.
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The last two decades have witnessed manufacturers of sustainment-dominated long field life electronic systems incorporate Commercial Off the Shelf (COTS) technology products into their systems on a large scale. Many of these products, however, have lifetimes of significantly shorter duration than the systems they are incorporated into and as a result become obsolete long before the system's intended duration of useful life is over. This problem is especially prevalent in avionics and military systems, where systems may encounter obsolescence problems even before they are fielded and always during their support life. Manufacturing that takes place over long periods of time exacerbates this problem. Many part obsolescence mitigation strategies exist including: lifetime buy, last-time buy, part replacement, aftermarket source, uprating, emulation, re-engineering, salvage, and ultimately redesign of the system. Design refresh (or redesign) has the advantage of treating multiple existing and anticipated obsolescence problems concurrently and additionally allows for functional upgrades. Hitherto, there have been studies concentrated on determining the optimum combination of different obsolescence strategies by using life cycle cost as the deciding criterion. However, these studies take into account only hardware life cycle costs. In many systems, such as avionics systems, software life cycle costs (redesign, rehosting and requalification) have a significant bearing on total life cycle cost. Thus software redesign due to part obsolescence triggered hardware redesign should also be addressed during life cycle management planning. This thesis describes a methodology and it's implementation for determining the hardware part obsolescence impact on life cycle sustainment costs for system software based on future production projections, maintenance requirements and part obsolescence forecasts. The methodology extends the MOCA (Mitigation of Obsolescence Cost Analysis) methodology/tool that determines the optimum design refresh plan during the field-support-life of the product in order to minimize life cycle cost. The design refresh plan consists of a set of design refresh activities and their respective calendar dates. The methodology incorporates the use of two software commercial cost analysis models: PRICE S and COCOMO. The methodology developed in this thesis has been validated using a Navy test case (VH-60N Digital Cockpit Upgrade Program). It has also been applied to Honeywell International, Inc.'s AS900 engine controller. The results obtained demonstrate the necessity of taking software redesign analysis into account during life cycle management planning.