Jim continues the discussion of the use of the construction schedule as a management tool. He explains how a construction schedule can impact productivity on a job site by avoiding things like trade stacking in order to keep the trade contractors productive at the workplace.
- Throughout this course, I've talked about the importance of proper planning, and the fact that it takes experienced people to properly plan a construction project. There can be a lot of activities to consider, and it takes experience to understand how some of these activities relate to one another. It's easy to see how poor planning can affect productivity at the site, but even with the best of plans, sometimes scheduling can impact productivity as well. Oftentimes, the contract will call for a required completion date, instead of a number of working, or calendar, days.
So there's a very specific target date for turning the project over to the owner. I worked on the foundations for a big toy store one time, and they had an absolute date that the building had to be turned over to them, so that they could stock the store, and be open in time for the holiday shopping. That date was firm, nothing else mattered to them. If they missed the holiday sales, they had no need to take possession of that building until next year. No pressure at all there, right? Sometimes when you're working with a fixed end date like that, and the schedule looks tight, you might have a tendency to start compressing things.
You call the contractor installing the shelving, and ask if they can supply a larger crew, and cut two weeks off the schedule, or you do what we refer to as stacking the trades. Scheduling the drywall crews into an area when the electricians aren't quite done yet roughing their work in. Because their tasks are so long, then on paper it looks logical to overlap them. The thing is though, sometimes this works, and sometimes it doesn't, it all depends on the project. Earlier we discussed the fact that during planning you have to keep in mind the logic of the workflow, things like getting the walls painted before the carpet goes in.
Otherwise, you're going to have to take extra steps to protect that carpet. When we schedule these work activities though, we also have to consider things like how much room is there. At some point, the space just might not be big enough to realize any gains in productivity by adding more people, because they just can't all fit and get their work done. Stacking trades usually has a negative effect on productivity, unless you really coordinated the activities between those trades. If that electrician shows up with a big crew ready to install everything, but they only have access to 25% of the space, that's going to be bad.
Can it be done? Yes, absolutely, but it takes coordination and reliability on each other to make it work and flow smoothly. Another issue related to the schedule and productivity is looking at the actual time of year that you have each activity assigned to, once that schedule is built and put on a calendar. Do you have concrete work scheduled in the middle of winter? Depending on where you are, there may be issues related to how much concrete can be placed at once, because it may have to be covered and insulated and protected from freezing.
Reconstructing an intersection that's the main entrance to a big shopping center over the holidays? That increased traffic and congestion may really effect productivity, believe me, I've tried, it doesn't work well, I've learned the hard way. Once you get these activities on an actual calendar, go back and look at them, and make sure that they haven't been pushed to a time of year where the productivity might be impacted by outside influences like weather, or traffic, or things you can't control. Always keep in mind, schedules have to be reliable and accurate in order to be a useful management tool.
This course identifies the steps needed to develop a proper plan, and demonstrates how that plan is transformed into a construction schedule. Throughout the course, instructor Jim Rogers shares examples of his own successes and failures in the areas of construction planning and scheduling, so as to lend real-world context to the concepts he covers.
- Types of schedules
- Planning versus scheduling
- Work breakdown structure
- Developing a schedule
- Creating a network model
- Assigning durations, costs, and resources
- Identifying the critical path
- Letting the software do the calculations
- Checking and updating the schedule
- Scheduling's impact on productivity