One of the residential buyers plays guitar in a band. When we took him to the construction site, he was glancing at the buildings and fully taking in the massive, physical result of human efforts. Then he said to us: You must be proud! Well, we are but it’s not our achievement, we explained. What you see is the outcome of hundreds of skilled, trained people performing their craft work with a specific concern for the next trade, leaving no obstructions. He paused for a few seconds and glanced at the buildings once more before he turned to us and replied: How is that even possible?!
Takt, or takt time planning, is a method for production planning and control including certain standardized processes and principles which – we would like to add – should be adjusted to the type of building, and thereby project, it is applied. Above all, takt is about creating harmony between people contributing to a common cause – whether it is to perform a piece of music or construct a building. In both cases, you are fundamentally dependent on skillful persons, who do exactly what they are supposed to do in a timely and considerate fashion because only then will the result be productive in both a strict and wider sense of the word.
We work for a general contractor in Norway. In the following, we outline what has (so far) come to be our way of doing takt time planning. We base our experiences on a residential project where we are soon to hand over 342 apartments to an equal number of owners. The project is the first in several projects which include transforming a commercial area including old warehouses and stores into a whole new city district with around 2500 apartments, green areas, and infrastructure.
Workshop #0 – Reverse planning
Plan forward, think in reverse. Backward or reverse planning is a highly advised technique in the Lean Construction sphere. It addresses the importance of starting with your end goal and then working yourself backwards. We organize this in what we call workshop #zero. The reason is that we consider reverse planning a part of performing the pre-planning ahead of the actual planning process. In the pre-planning all major stakeholders are invited to have a saying, based on the overall question: How do we make sure to complete the phase in time without experiencing a huge peak in the manning situation? For example, can we start earlier with some of the work to even out the workload? What would be the ideal direction for the work to be done? Should we work ourselves upward in the building using the stairwell as defining for the zone division, or are there other more flexible ways of using the physical space? Workshop #zero is organized to trigger new thoughts and be open-minded about alternative ways of doing things. In musical terms one might compare it with a jam session. It is organized without extensive preparation but may very well lead to the development of something workable.
Workshop #1 – Post-It planning
Involve, involve, involve. We plan forward. Workshop #1 is used to define the sequence of work. For this, a post-it planning session is applied. Every trade has a specific color on their notes. The trades are ideally represented by their crew leaders. Ahead of the workshop, all participants are given homework which includes to look closer into, and write down, the details of their work in the phase. In the workshop, a post-it planning session is arranged to find the right sequence and to start bundling activities into work packages. Important here is to let the discussions flow without interrupting the trades. In return, you gain a sense of ownership by the crew leaders which might come in handy once the plan is brought into life and things tend to tighten. If the trades were an orchestra, we imagine a music booklet could be handed out and immediately recognized by the crew. But if the trades instead form a jazz band, we suspect the drive to make a piece of music their own would promote a more open-ended approach.
Perfect harmony. Workshop #1 releases a new round of homework. It requires every trade to estimate the amount of work to be accomplished in the phase. In a residential project where takt is applied for the inventory work, the single apartment makes up a natural unit to do the estimation on. Workshop #2 is arranged to define the zone size, and final plan. In the workshop, each trade must balance their workload to the takt. We prefer a weekly takt. A weekly takt is long enough to allow the trades to adjust if they – for some reason – should fall off the wagon.
Takt Train with carriages containing work packages
When defining the zone size, our main question was how many apartments to include in a zone. For obvious reasons, we did not get a unison answer to this question since the workload differed between the trades. To end up with a unified zone size, we chose the following approach:
1. We gave the trade with the heaviest workload a prioritized saying. After all, their capacity strongly influences how many apartments are reasonable to include in a zone
2. We worked with more than one alternative zone size, not least to make sure the right level of involvement by all the trades
3. To visualize the consequence of different zone sizes, we prepared a spreadsheet including the apartments which were matched with workload estimates for every activity and trade
4. Once the zone size was decided we challenged the trades to think “out of the box” and cross-functional in the final bundling of activities into work packages – to fit their manning with a weekly takt
5. To the extent a weekly takt was still not compatible with the number of estimated man hours, the trades were encouraged to identify buffer work/work which could go on in parallel with the inventory work to maintain an even manning throughout the phase.
The result of workshop #2 is the final takt plan. It resembles a perfect harmony, just like a score including all the voices and instruments in a piece of music. Applying it to the everyday world of construction, one can be certain that to achieve something close to harmony between the trades requires a great deal of attention, facilitation and not least improvisation so that everyone can concentrate on doing what they should do – and do best. But that’s another story!