After the long lunch we had, I’m open minded and ready for anything. I tell Gary, “you said we have plenty of safety time in our projects, and that we are not using it right. I agree. We also have to break the vicious cycle of adding more and more safety to our projects.”
“I”m glad you are open‐minded about challenging some project management conventions,” says Gary.
“You will have to re-plan your existing projects and include these things in all new projects. Are you ready for that?”
I say, “Look, we have been struggling with so many issues, our performance is as worse as it’s ever been, and many of our customers have lost faith in us. It’s time to do something different. If we have to re-plan everything, I’m assuming it’s necessary to get the results we want.”
Gary says, “it may not be as bad as you think. The work content is not going to be any different and your budget is not going to be effected. We’ll focus on reducing the task duration estimates which will lead to reduced project lead times. We will address the issues you are struggling with. On time performance will improve. And, your lead times will become competitive again. I’m confident about it, how about you?”
“The day things start to turn around can’t happen soon enough. In a short time you have been able to understand our environment and show us a way out. I did have to give up on some preconceived notions about project management. We need to understand the actions we need to take.”
Action One
“Great! So let me explain the first of the three actions I recommend we take. Currently, you have safety time protecting the performance of each individual task. To stop doing something, sometimes all we have to do is the opposite. So, the first step is the reduce the task duration estimates to only the touch time.”
“How do we do that? I’m understand why we should do it, but I see some potential issues with doing that,” Jim says.
“I know which ones you are thinking about, but I assume you they will be addressed,” say Gary.
“During the planning of the project, imagine the assigned resource(s) working on the task without interruption. They have everything they need to do the work. They are away from emails and the phone, and they can work at a normal pace. The task exit criteria is also available so they know what “done” looks like.”
“This is hypothetical, right, because putting a person in that situation will be hard to do around here,” Jim says.
“Of course, imagine it for now. During the actual planning, by putting people in this scenario will help them think. It will also help provide you with a duration estimate closer to the touch time. Remember, folks are used to including safety in their tasks estimates it’s almost an unconscious decisions. The estimate needs to be good enough and nothing like the durations they’ve provided before. During this exchange with the resource, you can also check to see if they have any concerns. Concerns about where the safety time went. How they will protect themselves from Murphy. Or, how they will manage their stress levels.”
Action Two
“But, where does the safety time go? That’s one of my concerns, too. Don’t we still need some protection from all the variances and the visits from Murphy that occur,” I say.
“Yes, and I’ll show you how to address those issues in a few minutes. The second change you need to make is to calculate the longest leg of task and resource dependencies. To determine the length of a project we need to take into account not only the task dependencies, but also the resource dependencies. This is called the critical chain. The critical chain also eliminates resource contention within the project. In other words, a project schedule created with the critical chain method will not force any resource to multi-tasking.”
“That’s good to hear. We don’t need more things encouraging multi-tasking. I have heard of the critical path method and realized a few weeks ago we must take resource dependencies into account, too. I didn’t know it was called critical chain. Anyway, I imagine to calculate the critical chain, we will need some kind of specialized software?”
“Yes, a project or a portfolio of projects operating under the critical chain rules requires software. It’s too cumbersome otherwise. But, I don’t want to talk about that now. Let’s wait until you see the whole picture and then you can decide if you need it or not.”
Action Three
“That’s fair. What happens after you identify the critical chain?”
“Let’s address your issue about where the safety time goes. If it’s not embedded in each task, where is it? Remember when we talked about task variability; task durations usually vary around the median of the planned duration. Our assumption is that the safety time required to protect a series of tasks is smaller than the sum of the safety required to project each individual task. In other words, statistical fluctuations average out. For a path composed of sequential tasks, the reality is that the variances of the path are smaller than the sum of the variances of the individual tasks. It’s this fact that makes it possible to reduce the lead time of your projects.”
“OK, that makes sense. I still don’t see where the safety has gone. What else happens?”
“Let me ask you this, what’s more important––finishing each task on time or finishing the project on time?”
“The project, of course.”
“Of course, that’s how your company gets paid, by finishing and invoicing a project. You get nothing for finishing a task. So, let’s put some protection against what we vakue the most. The software will insert a shock absorber at the end of the longest leg, the critical chain. This will protect the project’s due date against the variability along the critical chain. Based on our vast experience, using 50% of the critical chain’s duration determines the size of this shock absorber. We call it a project buffer.”
“So this project buffer is where the safety we took out of individual tasks went,” said Jim. But what about all the other tasks, or non-critical chain tasks, not included in the critical chain?”
“The software will also add a shock absorber to the end of each feeding leg. It’s also 50% as long as the duration of the feeding leg. We call it a feeding buffer.”
“This feeding buffer will help protect the critical chain tasks from the variability along the feeding legs. It may seem like there is double protection by using two different, but similar buffers. But, realize the majority of the tasks will be in the feeding legs. Only about 10% of the tasks in a project are on the critical chain. The remaining tasks, or about 90% of them, are where most of the variability will occur. So, the level protection is necessary.”
“At the end of the critical chain and at the end of each feeding leg are excellent places for safety time. I can also see now why we need software. There are too many calculations to do by hand or even by using a spreadsheet,” I say.
“Believe me, I’ve tried doing these calculations by hand. There was a time before software was available and it was a frustrating and cumbersome process. I swore to myself I wouldn’t use the critical chain method until there was software. It finally arrived on the market two years later.”
Action Summary
“Anyway, in review, these are the three, new things you need to do when planning, or re-panning existing, projects:
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- Determine the touch time and estimate the task durations.
- Calculate the critical chain of the project.
- Place a buffer at the end of the critical chain and at the end of each feeding leg.
“That’s it, seems too simple,” I say.
Gary quotes Einstein, “Everything should be made as simple as possible, but no simpler.”
“There is one more benefit of using software. Imagine the day arrives for the project’s formal kick-off meeting. All the participants are in attendance. Your customers, key sub-contractors, outside vendors, and our project team are also there. You can review the project’s objectives, milestones, risks, deliverables, etc., and the proposed due date. If any adjustments need to be made to the plan, you can make them on the spot, in real time, and provide everyone with the final plan. You can announce the planning phase complete!”
“Nice! Is the next step to start the project?”, I ask.
“Yes, when you are ready to do so. There are new elements to be aware of during the execution phase. There are only three of them, too. Want to hear about them?”