What we Found
When we started looking closely at other industries, we noticed that keeping the site clean was a very important aspect to being efficient. Looking closer at our own job sites, we found that waste from the typical construction site added 5% to the overall cost of the project (in terms of cleanup and haul-off) and 10% was added to the schedule and overall timeline. The next thing we noticed was that the critical path could be drastically changed by lowering the number of people in each crew but allowing more crews to work in tandem. Closing down the home for large crews like painters, for instance, was extremely inefficient. Even working as fast as they could, it still caused a massive critical path in the project schedule that could not be moved or changed. Another disadvantage of large crews was the inefficiency of human movement and the re-work it often created. Think of a large grocery store packed with people. Efficiency is lost with that many people trying to move around, and items tend to get scratched or broken in the chaos. Lowering the number of staff on a crew, however, was not intuitive to our trade partners. They just don’t typically work that way. It took many conversations and much discussion to convince them that this would actually be better for them and for the overall production schedule. Several other items we noticed:
- Re-work is a significant problem on a construction job site, especially when many items on the job take 6-8 weeks to re-ship.
- Misplaced items are the cause of significant delays on a construction jobsite.
- Delayed shipments, products out of stock, broken or missing parts, or a miscalculation in material quantities are another cause of significant delays.
Builders tend to add contingency in the schedule for all of these delays. It can add up to 6 months to the schedule for these issues. For larger homes, those over 5,000 s.f., the problem is compounded, which is why you have seen some larger homes in the area under construction for up to two years or more. That’s why our system had to address all of these things.