Case Studies in Maintenance and Reliability: A Wealth of Best Practices. V. Narayan
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Название: Case Studies in Maintenance and Reliability: A Wealth of Best Practices

Автор: V. Narayan

Издательство: Ingram

Жанр: Физика

Серия:

isbn: 9780831190552

isbn:

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      8.8 Results

      This proved to be a very successful process. In the initial stages, there was some resistance, especially from the poor performers. Within two years, results from those locations who took part in the process demonstrated the value of the process to the rest. We had refined the process itself continuously during this period, so new entrants experienced a mature approach. We had a high demand for this service, with a waiting list of about 18–24 months. The head office expanded these services to third parties on a commercial basis. Eventually the unit became a major global service provider in this area.

      8.9 Lessons

      1.Busy people at busy facilities do not welcome demands from the head office for information, especially if that information might be used to show them in a bad light. So when collecting data, try as far as possible to use information in existing reports and returns. The fewer times that demands are made on a site, the more likely it is that they will report accurately and on time.

      2.Perfection and absolute accuracy are the Holy Grail, but not worth the benefit. The aim should be to produce a good enough result with as little effort as possible.

      3.Top performers run their businesses in a similar way, focusing on a number of key aspects, which bring business benefit. These are well known, as are the factors, which don’t matter significantly.

      4.Poor performers put their efforts into excuses and the wrong things.

      5.When giving advice to sites, it is important to be welcomed. You can’t force people to take advice.

      6.Measurements need a consistent set of definitions measured in a consistent way.

      8.10 Principles

      1.Knowing where you are is the first step in an improvement effort. Knowing what to do about it is not always obvious. We can seek recipes from top performance—and use them.

      2.In-house and inter-site comparisons will take you a long way, but it can become incestuous and self congratulatory. The market is the best leveler; it is necessary to benchmark against others.

      Appendix 8-A

      Vocabulary and Terminology

      8-A.l In-House Terminology

      Plant availability, reliability, and utilization are shown diagrammatically in Figure 8-A.1.

      8-A.2 Benchmarking Consultant Terminology

      One leading consultancy dealing with refinery benchmarking uses a term called Equivalent Distillation Capacity (EDC) as a measure of size and complexity. The following definitions are based on their web site, presentations, and publications.

      Annualized Turnaround Cost. Total turnaround costs divided by the turnaround cycle in years.

      Availability. 100% minus (annualized turnaround downtime plus a two-year average for routine maintenance downtime)

      Average Run Length. Mean on-line time of a process unit between stops. Complexity. Refinery equivalent capacity divided by crude intake capacity.

      Equivalent Distillation Capacity. EDC of a unit is capacity multiplied by complexity factor. Total EDC of a refinery is the sum of the EDCs of individual units. This refinery EDC is used as a divisor to normalize aspects such as costs, personnel numbers, etc.

      Equivalent Maintenance Personnel. Total number of company’s own man-hours + number of contractors man-hours + annualized turnaround man-hours including all overtime divided by 2080 (52 weeks × 40 hours).

      Maintenance Costs. Total maintenance costs including capital replacement items, averaged over two years for routine maintenance and over a complete cycle for turnaround maintenance.

      Maintenance Index. Maintenance costs divided by EDC.

      On Stream Factor. 100% minus percentage of all downtimes (maintenance and others).

      Replacement Value. Investment needed to replace refinery in its same location.

      Routine Maintenance Index. Routine maintenance costs averaged over two years divided by EDC.

      Turnaround Maintenance Index. Annualized turnaround costs divided by EDC.

      Utilization%. 100 × total annual intake in bbl divided by (365 × annual design capacity in bbl/day).

      Discussion on Normalizing Different Facilities

      8-B.1 Possible Normalizing Factors

      The following lists a number of normalizing factors usually used to try to cope with the differences found in facilities:

      •Intake barrels or tons

      •Replacement value (RV)

      •Mechanical complexity of the plant (MC)

      •Equivalent Distillation Capacity (EDC)

      People often suggest (especially the poorer performers) that as a basis of inter-refinery comparison, such lists can be misleading, unfair, and certainly limited in their use as league tables of performance.

      8-B.2 Comparison of Methods

      Conventional financial reporting is extremely difficult to use for performance comparisons between refineries for the following reasons:

      •Profitability. Return on investment or cash flows are not generally reported for individual facilities separate from their marketing and ancillary functions. They are too far removed from the supply sources and the market place to use actual trading values; therefore, transfer values have to be devised. These, however, are often driven more by taxation and where it would pay to take profits, than reality. Also, because of the volatility of market prices, results achieved do not necessarily reflect operational efforts.

      •Asset values. Such book values are distorted by financial practices as well as by varying capitalization and depreciation methods. Yet they do reflect the age of assets to a degree. Although useful in the business world, asset values are not a particularly useful basis for intersite comparison worldwide.

      •Volumetric divisors. Divisors such as intake quantities may reflect the size of a facility, but they do not make allowance for downstream costs of operating added-value processes, i.e., complexity/conversion factors. One leading consultant uses an Equivalent Distillation Capacity (EDC) which attempts to relate size and complexity. Many people express reservations about this methodology. It is rather artificial and difficult to sell the EDC concept to middle management and supervision as a motivating tool. People can see barrels, but not EDC. However, it has become widely used and accepted in management circles

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