Takt time planning is a great tool for aligning crews and creating flow on site. However, it’s still just a plan and it will inevitably fail at some point. One of the reasons for using takt time is not only to create flow, but also help pinpoint where the bottleneck is on site. In the long run that’s a good thing; don’t ignore your problems, they’ll just grow.
Aside from adding more crews, here are a few countermeasures to consider when executing a Takt time plan that’s gone off-beat.
Change the sequence
When the work starts, your assumptions may be proven wrong. If it’s going to be a universal issue through all the zones, it makes sense to change the sequence. Here are a few changes to consider:
1. Adjust the trade sequence but keep the same number of activities (e.g., maybe plumbing needs to go before electrical in-wall in all zones)
2. Change the sequence by adding activities to the sequence (e.g., framing with inspections may take longer, so split out inspections and make framing and inspections two separate activities)
3. Move the tasks within the activities themselves that make up the sequence. Typically, activities (e.g., electrical inwall, priority wall framing, etc.) contain several tasks within the activity. It may make sense to move work inside the activity to another part of the sequence. For example, if pulling wire is considered part of the electrical inwall activity and that activity is taking too long and doesn’t release the next activity, it may make more sense to move pulling wire downstream to level the work out.
Change the zones
Changing the zones may be a good solution if you realize the work is going faster or slower for some trades. The smaller the zones are, the faster you can go. This works great if the smaller zones still have a Takt time that is long enough to resolve problems in the time window. However, if that solution window is too small and there are too many constraints, then you may need larger zones (with longer corresponding Takt times) to accommodate the team’s ability to resolve problems. In general, I am all for creating a plan that starts with larger zones that you aim to break apart and go faster with time as the team gets more familiar with the plan.
Stop and catch up
If you are moving through the plan and realize that there are too many constraints and only 50% of the work can get completed as scheduled, then it makes more sense to stop and solve the problems. If you don’t stop now and there are many constraints out in the field, you will stop eventually, whether you want to or not.
In the spirit of building confidence of the team with the plan, it’s a good idea to also start with a slower Takt time plan that the team can achieve with high reliability. This aligns with the philosophy of “lowering the river to reveal the rocks”. As the team gets more comfortable you can always adjust the takt time to accommodate their improved speed.
Move the work out of Takt
Sometimes we get a little ambitious with setting up the plan and place work in the Takt time sequence that doesn’t need to be there (e.g., does installing thermostats really need its own sequence?). This is an easy counter-measure to abuse, but it is always a question to ask when setting up the plan and executing the plan. Should we be planning this work to a Takt time or outside of it?
Visualize what was missed
In all circumstances, it is important to identify the work that was not completed. This is one of the benefits of executing to a Takt time plan and zones compared to no zones and working across full floors. The ability to see the plan unfold at a higher level of resolution allows you to see variation and improve. When the work is tracked visually it is easier communicate the problem to the entire team and rally behind a new plan to catch the work up.
There are many ways to get a takt train back on track. Regardless of what is done, it’s important to communicate how the plan is changing and get buy-in from team members so everyone keeps moving in the same direction and at the same speed. When a problem occurs, you want to deal with it right away and you don’t want to repeat the same mistakes again.