Presentation of the Graphical User Interface

The implemented algorithm is composed by the three forms, whose content is here presented.

The first form, as already mentioned, is purposely designed to acquire the parameters relating to the specific enterprise in relation to its time management efficiency and process requirements. The user, then, is firstly asked to compile the boxes relating to the enterprise working days, the number of shifts per day and the duration of each shift (figure 4-5).

Figure 4-5: Initial form: enterprise and process data

The algorithm, then, will calculate the corresponding working hours in which the industrial plant is supposed to be operative (figure 4-6).

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Figure 4-6: Example of data insertion: calculation of the enterprise working hours

The following boxes to be filled in refer instead to some other specific data (such as the time spent in preventive maintenance, the discount rate, the planned machine lifetime, etc.), and include also the definition of the process conditions in which the machine is demanded to run (number of batches, number of pieces per each batch, percentage of faulty pieces, process time per piece, set-up time, and so on…).

Once the user has inserted the number of batches that will be processed on the machine, a table with all the parameters required for each batch will be instantly displayed, together with the button “Done”, predisposed to acquire all the values in the form, and to open the second form in which the technical data are contained (figure 4-7).

Enterprise working hours

Figure 4-7: Initial form: insertion and completion of all the required data

Since the first form is designed for having a complete and essential interaction with the user, a formal control on the input data is absolutely required, in order not to generate code exceptions. Then, once the invalid input has been entered, as already mentioned, a message box which notifies the error to the user is soon displayed on the screen (figure 4-8).

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Figure 4-8: Example of data insertion: error message for invalid input

After having pushed the “Done” button, the second form appears on the screen: here the parameters of the machine tool components relating to their energy consumption and to their technical, logistic and economic aspects (such as component MTTF, dimension and cost) are grouped in a table (figure 4-9).

Figure 4-9: Machine components parameters

It is worthy to note that the initial list of machine components presented in the third chapter of this thesis (see table 3-2, p.52) has been modified, including another element, the “Machine frame”. The reason of this additional component lies in the will to take into account its eventual influence on the lifecycle costs, even if it is not

Invalid input data!

related to any energetic consumption, but only to logistical needs. The hypothesis behind is to evaluate, for instance, the impact of the necessity to enlarge the machine structure for some production reasons (considering major component dimensions in virtue of a major power required and installed), or better for some safety reason (enhancing the frame dimension to better isolate the machine).

In the end, also the economic and supplier-based data, needed for the estimation of the machine lifecycle costs, are shown to the user in this second form through a data grid (figure 4-10):

Figure 4-10: Economic and supplier-based parameters

No interaction with the user has been then implemented in this form, except for the presence of the button “Calculate LCC”, through which, after its pushing, the third form containing the results can be open and displayed. The complete representation of the second form is hereunder illustrated (figure 4-11):

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Figure 4-11: Second form

Finally, the output data required are resumed and grouped in the third form. In particular, the results concern:

 the machine tool lifecycle costs;

 the machine tool annual cost;

 the cost per part;

 the component energy states.

In regards to the machine tool lifecycle costs and annual cost, the algorithm is set in order to place the results in the left side of the form and highlight the total sum and the annual share (figure 4-12).

Figure 4-12: Example of LCC results presentation

The cost per part and the component states are instead positioned in the right side of the form and their content is displayed in two data grid: the first one includes the number of produced pieces per batch, then the theoretical cost per part, the number of faulty pieces and the actual cost per part (figure 4-13).

Figure 4-13: Example of Cost per Part grid

The second grid, instead, shows only the different energy states (Process, Idle and Hibernation state) for all the machine components. The purpose of displaying their energetic conditions is to highlight the machine tool parts that are more demanding in

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terms of time and power requirement, and then in terms of costs. This is useful in order to put the basis for a further research with the aim of evaluating how the energetic impact of certain components on the whole machine can be reduced by the improvement of their technical characteristics and performance (figure 4-14).

Figure 4-14: Example of component states grid

Finally, the complete representation of the third form is shown in the picture below (figure 4-15):

Figure 4-15: Third form

4.2 Summary

In this chapter, a brief and illustrative description of the algorithm “LC€nergy” for the calculation of the lifecycle costs related to the energy consumption of a machine tool has been presented. In particular, a general overview on the structure of the code and of the graphical interface has been proposed, enhancing the reading through the use of the pictures relating to the different forms described.

In the next chapter, a complete evaluation of the concept and of its algorithmic implementation will be provided, in order to test both the logical coherence of the model, and its computational compliance in terms of output efficiency.