Hierarchy of Control

National Institute for Occupational Safety and Health, Public domain, via Wikimedia Commons

In construction we are familiar with the graphic above when it comes to controlling safety hazards. I suggest that it also applies to the other challenges that we have on our sites. Do our sites go over budget? do they go over schedule?

What are the equivalents that we can compare to the systems that we work in?

In the extremes we would have Elimination, where we redesign the system. We take the time to understand the value flow within the system and eliminate the wastes. We manage by means and ensure that people are following the system as designed, the system is modified of the outcomes are not what we want.

With Substitution, we look at the process that we are going to build and would use buffers to control against the variation in our system. The 3 main buffers that we use in construction are capacity, material and schedule buffers. This is where we balance an excess of these 3 items to make sure that we won’t be affected by the random events on our projects. For example, I could have extra door frames on site because I don’t know how fast they are going to be installed. Or, I could have an extra power trowel available to finish the concrete in case one of the ones that I have breaks down.

On the other end of the spectrum, where you find PPE, this would be the equivalent of motivational quality posters and chats from leadership where they come in to tell you to just do better and work harder. Like PPE they can be some benefit and they are easy to implement, but the effect is limited and the issues are still there.

For Administrative Controls, I see this as picking one thing that we are really going to focus on to ensure gets done right and all other things are basically left to their own devices. For example, a frequent one is elevators. We will be ready for elevator install no matter what, but other things are done out of sequence like having the tile in the lobby done so the elevator can be set, before the overheads in the ceiling are complete.

Our Make Ready planning and constraint removal is really a form of Engineering Control because we are isolating out the tasks that are not ready to be scheduled into work, and those tasks that are getting close to be scheduled we are guarding them and trying to make sure that we will have what we need so that we can schedule them when the time comes.

What do you think are some equivalents to the safety hazards and the process hazards that we have on our projects?

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