RAM refers to Reliability, Availability and Maintainability. Reliability is the probability of survival after the unit/system operates for a certain period of time (e.g. a unit has a 95% probability of survival after 8000 hours). Reliability defines the failure frequency and determines the uptime patterns. Maintainability describes how soon the unit/system can be repaired, which determines the downtime patterns. Availability is the percentage of uptime over the time horizon, and is determined by reliability and maintainability.
Why choose RAM analysis?
RAM has a direct impact on profit through lost production and maintenance costs. The main objectives of RAM analysis are to increase system productivity, increase the overall profit, as well as reduce the total life cycle cost — which includes lost production cost, maintenance cost, operating cost, etc.
Some significant figures are:
- As much as $100,000 per hour typical production losses can be sustained in base chemical plants due to non-availability
- In oil refineries, production losses are millions of dollars per year for every 1% of non-availability
- In oil refineries, the maintenance staff are up to 30% of total manpower
- Maintenance spending is one of the largest parts of the operational budget, after energy and raw material costs
- Each year, over $300 billion is spent on plant maintenance and operations by US industry, and it is estimated that approximately 80% of this is spent on systems and people to correct the unplanned failure of machines (Engineering Maintenance, 2002)
- The operation and maintenance budget request of the US Department of Defence for the fiscal year 1997 was on the order of $79 billion
RAM analysis is essential to the system profitability. Even small improvements in the effectiveness of RAM schemes make large additions to the bottom line. For more information on how RAM can help you, download our Introduction to RAM.
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