The success story of the pearlchain at MAN
Status: From plan to pull
The MAN Truck & Bus division, together with the Scania brand, which also belongs to the Volkswagen Group, and Volkswagen's Brazilian commercial vehicle subsidiary Caminhões e Ônibus, is one of the world's largest truck manufacturers. MAN produces according to the five basic principles of program management based on the motto "From Plan to Pull". Flexibility and delivery capability represent a clear competitive advantage, and so a mindset of "Production delivers every vehicle" prevails. In order to be able to practice this, various principles are required for managing the production program: realistic interpretation of "market service", program fixings in accordance with the MAN decision calendar, level changes with minimum lead times and vehicle reprioritizations when the order book is full only in direct exchange with other orders, i.e. large-scale rolling through is not permitted. In addition, the decision on high-priority orders from sales is ultimately up to production.
Challenge: The optimal filling of the bead chain
The pearlchain begins with "filling" the orders (converting the sales-side order backlog into assembly orders). The pearlchain logic in production is essential for optimal order processing in the production area; it maps the production sequence both for complete vehicles (trucks, buses) and for the associated components (axles, cabs, engines, etc.). The pearl chain is used to determine both the location and the sequence of orders. A reference sequencing solution is designed to ensure the optimal sequencing of orders with maximum flexibility in a networked production system, i.e. to map both final assembly and component production.
The following must be ensured for the model mix production line:
- optimal customer orientation by taking into account the customer bead chain (e.g. truck assembly)
- consideration of local criteria in order to obtain an optimum solution adapted to the prevailing conditions in each case
Solution: With the APS solution Sequencing to a stable bead chain
flexis AG's standard software is oriented to customer processes and has a very easy-to-use interface. Due to the various views, the solution creates a high level of transparency and at the same time allows a lot of flexibility in the configuration of the rule set, i.e. there are hardly any limitations in the rule definition. Rule violations are presented in a graphical online display for well-founded action taking. Sequencing results can be simulated for weighing decisions, e.g. to check the supply situation in case of plan changes.
Result: Nearly 100% sequence stability.
The pearl chain can only be used for logistical purposes if it can be kept stable:
The booking discipline of the employees is important here. At MAN, sequencing is recognized and accepted as a supporter across all divisions. Consistent reporting of sequence stability and violations helps with future decisions because the effects become immediately transparent. For example, a malus system has been introduced for suppliers, which also makes the effects of their actions apparent to them. The strategic goal of high sequence stability with the simultaneous requirement to avoid violations at all costs was achieved with the flexis solution and its integration into MAN processes. It did take some time until the bead chain was stable enough to provide the basis for further processes and optimization: However, the investments have now paid off several times over.
Source: MAN presentation; VDI 2012