Page 38 - Intro Predictive Maintenance
P. 38

Financial Implications and Cost Justification  29


            2.3 JUSTIFYING PREDICTIVE MAINTENANCE
            In general, the cost of any current maintenance position is largely vague and unpre-
            dictable. This is true even if enough data are available to estimate past expenditure
            and allocate this precisely to a particular plant item. Thus, if we are to make any sense
            of financial justification, we must somehow overcome this impasse. The reduced cost
            of maintenance is usually the first factor that a financial manager looks at when we
            present our case, even though the real but intangible savings come from reduced down-
            time. Ideally, past worksheets should give the aggregated maintenance hours spent on
            the plant. These can then be pro-rated against total labor costs. Similarly, the spares
            consumption recorded on the worksheets can be multiplied by unit costs. The cost of
            the maintenance strategy for the plant will then be the labor cost plus the spares cost
            plus an overhead element.

            Unfortunately, the nearest we are likely to get to a value for maintenance overheads
            will be to take the total maintenance department’s overhead value and multiply it by
            the plant’s maintenance labor cost, divided by the total maintenance labor cost. Even
            if we manage to arrive at a satisfactory figure, its justification will be queried if we
            cannot show it as a tangible savings, either resulting from reduced staffing levels in
            the maintenance department or through reduced spares consumption, which would
            also be acceptable as a real savings. The estimates will need to be aggregated and
            grouped according to how they can be allocated (e.g., whether they are downtime-
            based, total cost per hour the plant is stopped, frequency-based, recovery cost per
            breakdown, or general cost of regaining customer orders and confidence after failure
            to deliver). By using these estimates, plus the performance data that have been col-
            lected, it should then be possible to estimate the cost of machine failure and poor per-
            formance during the past few years or months. In addition, it should also be possible
            to allocate a probable savings if machine performance is improved by a realistic
            amount.

            It may even be possible to create a traditional cash flow diagram showing expenses
            against savings and the final breakeven point, although its apparent precision is much
            less than the quality of the data would suggest. If we aggregate the graphs for the cost
            of the current maintenance situation, and plot that alongside the expected costs after
            installing CM, as shown in Figure 2–4, then the area between the two represents the
            potential savings. Figure 2–5, conversely, shows how the cost of installing CM equip-
            ment is high at first, until the capital has been paid off, and then the operating cost
            becomes fairly low but steady during the life of the CM equipment.

            Put against the savings, there will be both the capital and running costs of introduc-
            ing a CM project to be considered, which are outlined as follows.


            2.3.1 Installation Cost
            Some of the capital cost will be clearly defined by the equipment price and any spe-
            cialist installation cost. There may also be preliminary alterations required, such as
   33   34   35   36   37   38   39   40   41   42   43