What does a ‘good detailed schedule’ look like?

Exploring “the frozen zone”

At the start of each project, we often ask our clients what they think a good schedule should look like. Depending on the interviewee’s role, we typically get the following answers:

  • The production manager would say: “feasible, cost efficient, clear, stable”. During such an interview, frustrations might pop up that could sound like “Don’t ask overtime in week 1 and then underutilize the capacity in week 2”.
  • The supply chain planner can indicate: “providing the customer with what he needs but with minimum inventories, it needs to be as flexible as possible”.
  • The process owners or process standardization teams might say: “the plan will be good if everybody has simply followed the standard processes. They are there for a reason.”

All of them seem to touch important aspects but their answers are clearly biased towards their own role. The production manager doesn’t take service levels and inventories into account enough. The supply chain planner, although in many cases he will deny this, might make abstraction of costs. The process owners can have a tunnel vision, valueing the execution of the processes they designed, over the actual planning results.

Below I give you my two cents on how the quality of the schedule (the short term plan) could be evaluated. Does it tick the boxes? Then, I think you’re on the right track!

In one of my coming blogs, I will also give you some hints on how you can evaluate the operational, item-level plan on the mid term (S&OE, MPS).

My two cents

  • Most importantly: Make your schedule feasible. Assure it can actually be executed within the knowledge you currently have. Of course, things can happen but at least the schedule should have set all teams up for success. You might not already know what you need to know to create a feasible schedule, but learn from the deviations to increase your knowledge and make a ‘more feasible plan’ next time!
  • Secondly: Make sure your schedule is stable in the frozen horizon for execution. You want to set up the operational teams for success. “Providing a very stable target removes most alibis for missing the schedule” as Vollmann, Berry and Whybark wrote back in 1984. It is a pity, after all this time, we still struggle applying what these giants have preached! You can argue on ‘how long you should keep it stable’ and many people might have different thoughts about it. Depending on the business you operate in and the flexibility in your organization to react, this horizon might be different. For sure, if you have on average 60 days of stock, the horizon in which you can reasonably keep it stable will be different then in a situation where you have 2 days of stock coverage. We should also not exaggerate this ‘stability’. You can read my previous (“Stability? Check! Now , what about flexibility?”) to get some insights in that question.
  • Thirdly: visualize the plan once it hits the floor and the status of execution. Make sure everybody in the area can see what the schedule looks like and enable people in production to see where they are versus a stable and feasible schedule. If it is feasible and stable, teams get a clear goal and will work towards it. It doesn’t need to cost a lot to simply visualize it.
  • Next: keep your systems updated. Although the visualization on the floor can still visualize the initial schedule (and the deviation in execution), your systems need to reflect the knowledge you currently have. This will allow the organization to prepare the next cycle . It also creates the needed transparency on the current status to the entire organization.
  • In all cases, make sure your plan is agreed upon with the different stakeholders. If we need a team to execute a part of the plan, let’s make sure we give them a fair chance to give their inputs prior to the execution horizon. That way, they can give their commitment, and planning can again learn from them. Of course, if you start a journey, you won’t get the buy in of every single team as the processes to get these agreements might not yet exist. But you can build up this process gradually.
  • Finally, it is important to keep a growth mindset in the whole planning approach. Make sure your plan gets better every cycle. How do you do that? Start by understanding why it was not executed and define how you could avoid this in your next planning cycle. Some of the deviations could be avoided quite easily, some others will require more fundamental work that might require some cross functional cooperation.

So where to start?

To conclude, it is really not rocket science, but you would be surprised how often it is not possible to tick the boxes. In such a case, you might wonder where to start. I would personally start with creating the stability. Once you have that, all other aspects will follow. Good luck!

References

Vollmann, T.E., & Berry, W.E, & Whybark, D.C (1984). “Manufacturing Planning and Control Systems”, Illinois: Dow Jones-Irwin.