Is your process plagued by bottlenecks? Does one of your project resources have a gnarled stack of job tickets on their desk? The uninitiated may look at that resource as the weakest link in your process, but a closer examination would point the finger to poor scheduling. Drum Buffer Rope (DBR) seeks to provide a solution to this resource overload through a limiting WIP principle.
Like the drummer aboard a boat banging out the pace for oarsmen, the Drum is the part in the process that sets the speed for all other steps, both down and upstream from it. Also, the Drum is the source of dependency for delivery in your schedule. I.E., you can only get as much out the door as the Drum can handle.
Again, it is easy to finger point and call the drum the weakest link in the overall process. But we know the reality is this resource is a sought after and valued team member on projects. They are subject matter experts and the go to person for that work. So, unless your agency hires their doppelganger, you need to revaluate your scheduling practices to help them.
If you’ve read my other posts on Limiting WIP, then you are familiar with buffer management. If you don’t feel like clicking on the convenient link I have offered, I’ll give you a brief of explanation.
The Buffer seeks to absorb variability by forcing constraints. This queues up task assignments for the constrained resource.
This is a concept that may be hard to swallow for the creative industry; the realization that increased efficiency in your workflow may in fact come from limiting the amount of work in process.
The rationale for limiting the number of task assignments for your Drum is the recognition that your resource is only human. As such, they can only get a certain amount produced in a day/week/month. We force the constraint to this resource by not allowing any new assignments to be done downstream that go over the buffer limit. That is to say, the component pieces of processes downstream cannot begin work on a new task that is out of scope of limits set in place; this where the rope comes into play.
The Rope is the pull system in DBR that ties the buffer to the downstream process components. When the buffer can accept new tasks, the Rope is the agent that fills the coffers for your protected resource. An ideal tool for the rope component can be found in the principles of Kanban; which is a job board that signals the workflow that new tasks can begin due to capacity in the system.
It may seem like a radical idea that limiting WIP can lead to increased efficiency. However, the managers in creative agency processes will surely know there is a constant battle to put out fires and manage chaos due to unpredictability of variability. Drum Buffer Rope offers a tool to force the constraint and control the points of variability.
So, do you think you could pull this off? Could you tell the owner of your company that we cannot start start working on a new job until the ones in queue are past a certain percent completion? Would their heads explode? As always, your comments are welcomed.