The predefined objectives consisted in the re-creation of the existing situation to evaluate the efficiency of the production system with a reduced number of personnel and under initial production conditions.
In fact, the final objective for this plant is to guarantee satisfactory profitability as well as product quality. These points are indispensable to make the treatment service, which is important for the community, also as economical as possible.
In this context, the simulation was performed starting from conditions involving limited quantities of treated compost and a reduced number of personnel.
In addition, since the plant is still in the start-up phase, faults and maintenance time were set on the basis of the data for this period; therefore, under conditions which are more severe than those hypothesised during normal operating management.
The simulation model was validated first by means of the graphic interface and monitoring of the control variables for an internal logic control. This was followed by a statistical verification examining the time development of the Mean Square Error curve for each control variable (see table I).
This curve is used to identify the minimum duration of the simulation run and therefore to reduce the uncertainty band of the final results to a minimum. Finally, an analog validation was performed through calibration of the control variables on the rated values for the machines still in the initial start-up phase and on the values measured for the components that were already tested.
