Selection and Timing of Measures

Number of days since last accidental release of hazardous material. This measure distinguishes between routine emissions (such as from storage tank vents, or low pressure steam discharges) and accidental emissions resulting from maloperation or breakdown. Events that might count would be safety valve releases, accidental releases into inappropriate drainage systems and unconfmed spills during maintenance. 

Number of days below plan emission levels. This measure generally runs through the plan period used by the organization, or as a rolling total over the last twelve months. This measure encourages analysis of emissions and their sources and can be used to help operators better understand how their actions influence emissions. 

As mentioned earlier some measures will be chosen because improvements in these areas were part of the project justification. It is most likely that these will be efficiency measures. Calculation of these measures generally requires analysis of data or specific data collection exercises. There is a relatively high cost associated with preparing these measures so they should be used prudently. In choosing efficiency measures, you should use only those where you have comparative data about the current management systems. For example, if there is no information on the number of hours dedicated to PSM and ESH, don t use this to try to demonstrate the improvement in efficiency. 

For many of the efficiency measures, the relevant data is collected during audits or by analysis of records. It is likely that your company has an internal reporting cycle with which you should coordinate your meas- 

Although it can be fascinating to collect as much data on performance as possible, there will be a diminishing rate of return. Instead, try to focus on the areas where the greatest opportunity for improvement existed, as were identified during your initial assessment. 

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