Shortcomings in process planning of manufacturing
Process planning means determining how, for example, a component of a truck engine is to be manufactured. A new doctoral thesis from University West and Chalmers University of Technology shows that there is a substantial improvement potential for this planning.
The starting point for the process planner is a drawing of the current component. In the case of machining, which the thesis principally regards, the first step is to select the machine. The process planner also has to determine the sequence of individual manufacturing operations such as turning and milling, how they should be performed and what cutting tools to be used. The process planner's selections have a direct impact on production costs and product quality.
On May 11 Staffan Anderberg defended his thesis Methods for Improving Performance of process planning for CNC machining - An approach based on surveys and analytical models. He has performed his research within the group Production Technology West at West University West and the defence took place at Chalmers University of Technology. Staffan Anderberg has, amongst other things, studied how the planning process is performed in a number of Swedish manufacturing companies today. He has found that digital aids are used to a lesser extent than what is possible. A major reason could be that the companies often do not receive designs of the components in digital form, that is as CAD models. (CAD stands for computer-aided design.)
"If you want to digitize and automate the planning process, then it is essential that you have CAD models to work with," says Staffan Anderberg.
Another problem is that companies rarely systematically collect and store data generated during the planning process. The experience then becomes bound to individuals. This often forces the process planner to collect the same information that someone else has already collected, when he or she begins planning.
Advanced computer systems, such as PLM - product lifecycle management, can be used in process planning to systematically gather information. But many companies have much work ahead before they find themselves in a situation where it is possible to start using these advanced systems. Staffan Anderberg says that other research work on process planning usually do not take this into account. In many cases the research is about an idealized world.
According to Staffan Anderberg, there is much to do at the basic level in order to systematize and make process planning more effective. In companies with a low level of digitalization other approaches are required than the often presented solutions. A first step is to obtain quantitative data on process planning performance.