Management of component obsolescence was seen as an important issue as early as the UMC development in the mid-1980s. Since then the approach of operators and suppliers alike has been generally limited to reactive component purchases. Some work on backwards compatibility for new systems has been seen in recent years, however, this is often limited by operator unwillingness to make firm future development commitments. This paper will look at how ongoing changes to the legislative and technical environment are affecting the obsolescence management processes within the subsea controls industry; specifically it will focus on the effects of the Restrictions on Hazardous Substances (RoHS) directive and die-shrink in the semiconductor industry. Having made the case for change, the paper will go on to present a model for proactive obsolescence management based around the concept of an obsolescence timeline approach tailored to the subsea controls industry. The paper will conclude with a case study, showing how this approach can be applied in practice.


This paper builds on existing work in the area of obsolescence, including presentations made at the September 2005 Society for Underwater Technology (SUT) meeting (Cretenet, Roberson and Bruce) on obsolescence in Aberdeen. It starts by reviewing strategies used to date in the subsea controls industry, comparing them to a generic set of strategies taken from the military sector. This is important, as obsolescence management from the military supplier's perspective is well developed and there is much relevant work the oil industry can adopt.

The main focus of this paper is on the electronic components, subsystems and products used in subsea controls. The issues raised and recommended approaches are, however, also relevant to obsolescence management across the oil and gas industry.

Existing StrategiesM

A list of strategies used to manage obsolescence in subsea controls equipment is shown below:

  • Do nothing

  • Push the problem down the supply chain

  • Spare parts holdings

  • Last-time buy

  • Standardisation

  • Emulation

  • Redesign

By far the most common approach has been ‘do nothing’ and, to be fair, to date it has proven to be workable strategy, but increasingly this is becoming a high-risk position for suppliers and operators alike. Depending where the company is in the supply chain ?pushing the problem down the supply chain? has its attractions, but in reality is no different (and potentially worse) than doing nothing unless the company actively manages and funds the process. The rest on the list, while less commonly applied, all have a role to play in obsolescence management but, taken individually, have their own problems.

Strategies Common to the Military Obsolescence Management

The list below is based on a presentation by BAE Systems for generic obsolescence strategies used in the military sector (Call 2005). The figures in parentheses provide an estimate of the average non-recurring engineering (NRE) cost associated with each solution on an individual part basis.

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