As an increasing number manufacturing companies move away from systems of mass production, they embrace lean manufacturing techniques instead. One of the most successful examples of lean manufacturing comes from the Toyota Corporation. Toyota minimized their reliance on information technology and made use of visual signals to manage the flow of materials and to handle scheduling. As companies turn to lean manufacturing methods as a way of boosting efficiency, a key question emerges.
How do advanced planning and scheduling (APS) systems improve the performance of lean systems?
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Pillars of Lean Manufacturing
A few key principles of the lean manufacturing philosophy help illustrate the role of APS in the manufacturing process. These terms and concepts include:
- Continuous flow: Unlike traditional batch production, continuous flow allows products to move through a system without interruption. Building one unit at a time, instead of collecting units into lots or batches, reduces waste and improves efficiency.
- Takt time: Takt time refers to the amount of elapsed time for the completion of a unit that will still meet customer demand. The term comes from the German word for an orchestra conductor’s baton.
- Production leveling: This method of “smoothing out” production minimizes fluctuations in the manufacturing process, and ultimately reduces waste.
- Kanban: The kanban system is a simple, but powerful, way to regulate the supply chain in a lean manufacturing environment. Visual signals communicate different kinds of information, including what parts to produce, and when to start and stop manufacturing. They also help identify how many parts need to be manufactured.
The Role of Advanced Planning and Scheduling (APS) Systems
APS systems can’t be compared with existing MRP systems. APS is a more sophisticated approach that accounts for capacity and relies on actual production system models. While MRP acts as an execution system to schedule individual operations, it violates a key principle of lean manufacturing. In lean manufacturing, operations scale based on customer demand.
The power of an APS lies in its use as a decision-making tool. An APS system makes high-level decisions that impact planning for the whole plant. However, the system also sets the schedule for departments and even individual machines.
APS System Capabilities
There may not always be a need to set schedules for single machines. A simple, manual kanban system may work effectively. In these situations, manufacturers use APS for planning purposes. APS offers the following functionality for planning purposes:
- Calculating takt time. Use APS in complex situations where multiple products with differing customer demand rates are manufactured on the same assembly lines. APS calculates takt time for individual items as well as for the entire line. It also creates optimized plans for the system to reflect changing takt times.
- Making decisions to develop the optimal pull system. Use APS to determine pack size, replenishment frequency, number of kanban to put in a given system, and much more. APS uses data to make these calculations, and it updates and modify these calculations regularly.
- Analyzing various factors and making calculations that enable leveled production. APS fulfills these needs while allowing visual control systems like kanban to execute the leveled schedule.
Advanced planning and scheduling systems play a key role in a lean manufacturing environment, complementing and improving lean initiatives. While physical production systems make the actual product, information systems boost efficiency and keep processes running smoothly. Remembering that advanced planning and scheduling systems are not meant to replace physical systems, but rather to enhance them is a key to success.