ALTHOUGH process manufacturing operations are extremely complex, recently there has been a tendency to oversimplify critical functions – for example, in the area of asset management.
To many plant-level professionals, asset management refers to equipment maintenance. To business managers, it implies deploying assets to meet business objectives.
Assets include plant equipment, energy, raw material, products, people, facilities, instrumentation, automation, information and time.
Maintenance improvements by themselves will not maximise business performance; in fact, they could degrade it.
Optimising plant assets to meet business objectives requires a holistic approach to asset management that considers both operations and maintenance. This has not historically been the case.
The traditional measure of operations is asset utilisation i.e. total output divided by the theoretical maximum output over a period of time.
Traditionally, maintenance is measured as asset availability i.e. the time an asset is available for operating over a period of time.
Most often, operations management drives improved asset utilisation and maintenance management drives improved availability, typically approaching each independently. It has not been clear as to whether improved business value is the result.
To improve asset utilisation, technologies such as advanced control, multivariable control, recipe management and process optimisation are used.
To improve asset availability, strategies such as preventive maintenance, predictive maintenance and reliability-centred maintenance are applied.
Most maintenance strategies are at the individual equipment level, with many focused merely on instruments and valves. This severely limits the value generated from asset sets.
Invensys defines effective asset availability and utilisation as follows:
• Asset availability: maximum output divided by theoretical maximum output.
• Asset utilisation: current output divided by maximum output possible.
With both definitions, there is a strong relationship between availability and utilisation that tends towards the inverse as availability and utilisation approach their maximums.
This inverse relationship presents a challenge to maintenance and operations teams because, the better they do their individual jobs, the more they negatively impact each other.
Asset performance management balances asset availability and utilisation to drive business value.
Since availability and utilisation are inverse functions, maximising them independently seldom results in maximum business value. In fact, it is often better to reduce asset utilisation over a business reporting system; this will result in fewer breakdowns.
To make these decisions optimally requires a measurement system that can provide business value insight into the desired operational balance between availability and utilisation. To achieve this, Invensys has a patented approach to real-time business measurement: dynamic performance measures (DPM).
These measure the business value of base assets, asset sets or groups of asset sets as a real-time vector that represents the true value that they generate.
Instead of optimising availability or utilisation, manufacturers can now optimise the business value.
The real-time business performance data enable a much more effective approach to true asset management. Rather than merely managing the availability of some instrumentation, plant personnel can drive business performance from asset sets, up to and including the entire plant.
* Commentary by Peter Martin, vice president of performance measurement and management, Invensys Process Systems