Install a Master Scheduler
A single, master plan drives the Maximum Flow System and the planning process is the responsibility of the master scheduler; he/she owns the process. While that may seem like an obvious statement, to many, it’s not. Those organizations do not employ a master scheduler or even have a formal planning and scheduling process – at least a process in the sense of a rigorous series of steps with checks and balances. A master scheduler manages and controls your organization’s capacity in the same way your controller manages your bank account. He or she writes “checks” against the capacity “balance” and ensures the customer needs can be met without overdrawing the account. Your capacity is as valuable to the business as your cash. Someone must be responsible for monitoring and managing this resource.
Make the Schedules Real
The master scheduler must create a realistic schedule, one that can be accomplished, not a wish list or a club to beat up the plant. While that also seems obvious, in many companies and organizations the schedule is used as a club to point out the shortcomings of production, saying in effect, “If production would follow the schedule, everything would be fine!” Equally ineffective is the schedule presented as a wish list, “Here is everything we have promised, try to get everything out.” Having a clear plan that has credibility is critical to driving execution behavior.
The schedule is a statement of the strategy; a “best” basis from which to execute; the strategy to win.
Drum-Buffer-Rope (DBR) gives you an edge in maximizing flow and productivity. Furthermore, DBR schedules are very reliable. The reliability of DBR schedules are what make them useful for creating a realistic model of execution and a reliable tool for decision making.
The key to the reliability of the schedule built using DBR is its focus on the main bottleneck resource of the system and its built-in protection against common-cause variation (buffer). It doesn’t try to plan every resource interaction in the system, so the plans it produces are much more reliable.
The planning process itself is also simplified. Since the bottleneck determines overall system capacity, planning is centered on that resource only, providing a simple plan that models the entire process.
Protect Deliveries with Buffers
Time buffers protect the delivery date; they are shock absorbers that protect the plan from process variation. Just as shocks on the heels of running shoes absorb the variations in the running service, time buffers absorb the normal variation that exists in every process.
Some people don’t like the idea of adding time buffers to the plan – they perceive it as waste. However, time buffers are a necessary safeguard against late deliveries. Don’t skimp on them by trying to be “Lean”; the goal of your order fulfillment process is to make the customer happy not efficient. Demonstrate that your order fulfillment process is under control by maintaining high delivery performance, then work on improving the process.
Time buffers aren’t just added randomly to any resource or area; they must be added to strategic locations in the process. First, buffers protect the drum resource and this, the output of the entire process. Second, a buffer protects the due dates of the orders. This assures that all orders are protected from variation.
My next blog post will focus on synchronized execution, the second part of the six parts of the system. Do you want to read ahead? Check out the full white paper titled “How to Build a Reliable Delivery Process” here.