Important Note: This question was inspired by an earlier question that was community-edited to fit PMSE's on-topic criteria. The OP's original question was considered off-topic, but it inspired this new question which seems answerable, if not canonically so.

When developing a risk management plan, one of the risks a project manager may want to address is the risk of team members leaving the project. This is often called the bus factor. A low bus factor could negatively impact project deliverables if the exiting team members have unique skills or knowledge that are not shared by the remainder of the team.

How can a project manager mitigate bus-factor risks to a team or project?


3 Answers 3


I think this is a great question for several reasons, mostly because it is an inherent risk on every project every time and largely ignored.

Attrition is normal and, in fact, can be beneficial when the rate of attrition is at that sweet spot where incoming and outgoing employees are at a good balance, and when you have a reasonably high performing knowledge transfer capability in place. So some of the impact of this risk is favorable, too, and some of your risk response would include enhancing and exploiting activities.

Part of this risk is inherent to all projects so you would not necessarily capture this on your register for more formal tracking, nor would you tie specific funds for your controls above and beyond the sort of normal 'keep your staff happy' activities. The other part of the risk, however, is discreet, like what the "bus factor" suggests. What scenarios exist that could threaten your staff capability? The answers to that question I would capture and mitigate specifically. For example, if you have to transport your staff from point A to B, some catastrophic event in transportation could occur. That would require specific mitigators such as using several modes of transportation.

One approach I use on nearly all my projects is to facilitate a near zero single point of failure from an employee perspective, i.e., I would minimize where I could that issue where an employee possesses unique skills and knowledge that I cannot replace as easy as I would replace a cog in a machine. Since we're dealing with humans, this is not as easy as a cog solution; however, my mentality is this so I pursue this type of resource acquisition.

We often get blinded by finding the best individual available and the best team available. Intrinsically, that makes all the sense in the world; however, that threatens your ability to replace them in a reasonable way.

I assume that the performance distribution is triangular and positively skewed, as in this picture: enter image description here

While it seems like a good idea to find folks who live on the right side of the triangle, replacing these folks because of these inherent risks means you will have difficulty finding them.

In the circle is where most of your practitioners live, where you are very likely to find a replacement easily and where your performance gap between these guys and the ones who live on the right are largely immaterial or acceptable.

So this is more of a mental approach than something I can actually measure during employee selection. When I begin to overly rely one a single individual and start to get the sense that I can't do without that person, I begin my intervention. I will close that gap so if that person leaves I can shrug it off.

  • +1. This obviates a huge risk in projects. Only thing is to ignore the obsession on perfectionistic output and target towards viable output which will benefit both the customer as well as project manager..
    – Muthu
    Commented Dec 28, 2013 at 1:00

Although you focused the question on mitigation of the risk, I think the first step is a really strong risk assessment. What is the impact of the bus factor on your ability to deliver?

This is a problem on one of the projects I work; we rely on a key skill that is difficult to acquire. Our lead tech/architect left to take what he described as his absolute dream job; it took us over 9 months to find a replacement, and we had to raise the amount we were willing to pay. The HR department should be able to estimate the cost of hiring a new employee, and sometimes the time. The impact to the project is the cost of the station keeping time while you locate and hire that new employee, plus a month or so to get them up to speed. I am willing to bet that the total cost to the project will be quite large. Make sure management know that this is the risk you're trying to mitigate.

Probably the best mitigation is to bring on a junior RIGHT NOW. That lowers the cost because you can hire someone who is not fully trained, and eliminates the onboarding cost and the "spinning up" cost. Those two costs may be sufficient to justify the salary of the junior skilled person. You've got to make sure you invest in a junior who can grow, and you probably should evaluate the cost of being wrong at a lower probability.

The alternative - and we did this on a prior project - is to put a highly skilled expert on retainer. Find someone else in the organization or who could be made available in case of an emergency and brief them up on the project, the technical approach, etc. If the bus hits, the expert can take over. Although this is in some ways the best cost/benefit, that's largely because you're concealing a financial cost inside a political cost; you're going to pay heavily in favors and governance for this arrangement.

The third option is to hire a pinch hitter. Short term high expertise contracts cost a significant premium, but they are available and they can make the difference between a project succeeding and a project catastrophically failing. If you raise the price high enough, you can get an expert to fly in and take the job for short to medium term. I would advise making sure you know what this would cost; If I'm going to walk into my bosses office and make the case for a junior staff, I'm going to compare that salary against two possibilities - either project failure, or a pinch hitter.


Cross-skilling your staff and having back-up resources for resources-at-risk are common practices. Also, you should have a well-defined KT process and KT should be a prerequisite for a clean exit from your organization

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.