Simulation Comparison Parameters (Last part)

(IV) RESOURCE UTILIZATION

The most common indicator used in practice is average resource utilization. This indicator provides good overview of the shop performance.

The average resource utilization can be defined as summation of resource utilization over all resources divided by total number of resources. Logically, a higher value of the indicator is a sign of better performance.

Average Resource Utilization = ∑ (Resource utilization across all resources) / No. of resources


(V) SERVICE LEVEL

This is one of the most common performance indicator used to compare the simulation results. In fact, this is one of the highly acceptable indicators to evaluate performance output of planning and scheduling activity.

Service level indicator is normally calculated in percentage.

Service level is defined as percentage of the orders completed within the due date criterion. This means, it gives the percentage of the orders those are completed with zero tardiness.

Service Level = (Total No. of Order – No. of orders with zero tardiness)/(Total Number of orders)

The above value multiplied by 100 gives you the percentage value of service level.


(VI) RESOURCE USAGE COST

There can be multiple derivatives for calculating production cost and related indicators. As at present, in Incoplan, only one cost parameter is defined, which is cost of resource usage, which in turn can provide a fraction of production cost.
This value can be defined as production run cost or resource usage cost.
The value can be defined as:

For all resources -
Resource usage cost = ∑ [Resource usage time*usage cost per unit time]

(VII) Q – RATIO

The Q-ratio is also one of the good indicators about your schedule. This is the ratio of work content to cycle time. As this indicator has direct reference to the work content, in a capital intensive industry, where the resource usage is critical, could provide a good guideline to understand the manufacturing performance.

Q Ratio = ∑ [Work content for all orders] / ∑ [Production cycle time of all orders]
There could be other different ways to calculate this value with respect to work content and cycle time.

Let us try to understand, what these calculating parameter means. We can again refer to the same problem, what has been defined earlier. In the following illustration, you can very well visualize meaning of work content and cycle time.


It is interesting to note that if the value of Q ratio is one [1], the sum of all work content is equal to the sum of production cycle times. This means, the unproductive time on resource is zero. Obviously, this is not possible in practice because of process constraints and priorities.
For the guideline, we can observe the following value pattern to identify comparatively better performance.