**Author details**

to the role of a spreadsheet with active macro application option, which allows to compile input data for computer aided design (CAD) and computer aided manufacturing (CAM) systems and control their correctness, completeness, consistency and adherence with the allowed range. Diagnostics of data is a significant element that influences comfort of using the design system. Full integration of a spreadsheet with popular CAD systems is possible nowadays, which significantly facilitates structural designing and drawing up documentation in the form of drawings. At the same time, a spreadsheet allows for drawing up a data file for a parametrized program of processing a selected class of produced machine parts by using related data sheets. An Excel Macro-Enable Workbook (XLSM) format file allows to use macros, that is, command sequences that might be used for the automation of completed functions in a spreadsheet. A 3D model is made by preparing a drawing in CAD program, which is integrally linked to the data included in the spreadsheet's data file. Then, 2D documentation is made based on such model, if it is necessary. The code generated in a spreadsheet has a simple structure in the form of a list of R-parameters plus the name of a processed part. These are input data for CAM system and/or the numerical control system of the machine tool, where parametric programs related to the aforementioned list of variable parameters are archived. Aside from formal verification of the controlling program's form, processing in CAM aims at providing a simulation of processing. Aside from confirming correctness of programmed trajectories of a machine's movement, the simulation made provides an exact completion time for individual processing operations. The results are exported to the Petri Nets Modeler (PNM) package, which allows for exact time simulation of a production unit's work. A list of Petri network model transitions in XML format are again transferred to the spreadsheet, thus closing the process chain. It includes a list of transitions with their completion times and a number of repetitions in a given period. A spreadsheet allows to easily obtain a clearly structured document presenting, for example, utilization rate on production

PNM package is a key module of the presented design system. Its objective consists of computer simulation, modeling and optimizing of both individual and group processes of production, dedicated to autonomous flex-cells, multi-machine tool stations and robotized

Both the very process of planning manufacturing processes and the structure of the manufacturing processes require applying a conditional-event mechanism that is naturally represented in the Petri networks technique. This chapter briefly outlines the broad opportunities of applying this technique to design of discrete production processes. The period 1990s are the most intense development period of Petri networks technology. We are currently at the stage of applying already mature programming tools, increasingly frequently integrated in heterogeneous planning systems. The greatest advantages of Petri networks technique visible and acknowledged by engineers include: an opportunity to generate models with various levels of

resource (**Figure 5**).

52 Petri Nets in Science and Engineering

manufacturing systems.

**7. Summary**

Roman Stryczek

Address all correspondence to: rstryczek@ath.bielsko.pl

University of Bielsko-Biala, Poland
