A Simulation Program for Forecasts of Production at Tetra Pak Packaging Material AB in Lund

Sammanfattning: Tetra Pak Packaging Material AB (TPPM) is the division within the Tetra Pak concern that produces the packaging material that later on will be used for liquid products. There are 63 TPPM plants in the world, and the factory in Lund is one of the largest with its 325 employees. It is also the TPPM factory that manufactures the most varied set of packages. There are nine producing machines, divided into three machine groups: printing machines, laminating machines and slitting machines. The department of planning at TPPM plans the orders with the help of a program called ProPlanner. What they lack is a tool to predict the lead times of the planned orders and the capacity of every machine during a specific period of time. This tool should complement the ProPlanner. To solve the problem we decided to make a simulation program. The reason we did so is that there are so many random events that affect the production so it is hard to calculate forecasts by using a deterministic method. The software we used is called AutoMod and it is a simulation program especially made for simulations of production and materials handling. After having studied the processes of production at TPPM, we structured the simulation program and collected the data needed for the program. The parameters used were: ? Set Up times for the machines ? MTTR (Mean Time To Repair) ? MTBF (Mean Time Between Failure) ? Run speed for the different orders in the different machine groups ? Planned stops in the machines ? Stops during weekends in the different machines An important thing for this project was that the user interface of the simulation program must be user-friendly. All parameters must be possible to change and to do this we have created an easy-to-use Excel interface integrated with the simulation program. The output from the simulation is also displayed in this interface. The reliability of the output gets higher if more than one run for every simulation is made. It is possible to do 1-100 runs, and tests of the program showed that at least 30 runs should be made to get an accurate result. The simulation program will help the personnel at the department of planning at TPPM. They can control if the lead times of the orders, as they are planned, will exceed the predetermined due date and if the capacity of the machines are enough. As all results from the simulation program are forecasts, there are no guarantees that the future will look exactly as the forecasts. If no dramatic events will occur in the production line, though, the program will give a good general view of the production in the near future.