3 Common Mistakes Using Gantt Charts For Medical Device Projects

In this series of articles, I’ll touch upon areas that I’ve found to be practical advice for project leaders. This article will focus on project planning. Hopefully, the points made will benefit you in supporting or running your next project. As project leader you need to develop a project plan for your team to track their tasks, as a means to see where you are with respect to the project deadline or product launch, and as a way to communicate to management how things are tracking. There may be other uses for a project plan but these are the main ones.

Now that you’re a project leader, your job is to get the project done as soon as possible and get it done right; management is already breathing down your back. Quickly, you assemble your team, now what? The next thing you need is a project plan: what needs to be done, what you need to do a task, when a task needs to be done, and who needs to do what. How best to accomplish this? A Gantt chart.

A Gantt chart is a bar chart used to show a visual timeline of a project and its tasks. It provides a step-by-step road map of the project’s timing, milestones, and overall timeline. Basically, it shows how the project will unfold. I worked at many companies that utilized Gantt charts to control and monitor projects. They are a useful tool, but, like statistics, they are only as good as the inputs from which they’re constructed.

What’s ironic about a Gantt chart is that it is supposed to show a detailed overview of the project, but you compile the Gantt chart at the beginning of a project when you know the least about what actually needs to be done, how long it will actually take, and what issues and obstacles you will face. In effect, you are predicting the future that you hope will happen and the way and when it will happen. What’s worse, once you determine a completion date based upon this conjecture, everyone, especially management, will expect you to make that date. For this reason, some project teams will fudge their completion date by padding the time allotted to individual steps to push back the projected completion date.

Mistakes often occur in developing a project Gantt chart. It’s inevitable that a step is missed or the time it takes to complete a task is underestimated. Of the mistakes made with Gantt Charts, three typical mistakes are: not enough detail/steps delineated, unrealistic timing assigned to project steps, and not keeping the Gantt chart up to date. Let’s take a closer look at these mistakes and what can be done about them.

Mistake #1: Not Enough Detail/Steps Delineated

In putting together a Gantt chart, a lot of teams will define general steps and gloss over the actual number of steps. For example, a company requires a protocol for any testing to be conducted. The protocol needs to be submitted for approval, which is defined in company documents as taking a minimum of 10 days. Once the protocol is approved, materials may need to be procured and time set aside in manufacturing to run the protocol. Lastly, the results need to be compiled, analyzed, and a final report written, which is then approved. Here is a simplified summary of how the project team listed this in their Gantt chart:

STEP                               DURATION                  START DATE               END DATE

Write Protocol            3 days                               Monday, 6 Feb                Wednesday, 8 Feb

Protocol Approval     5 days                               Thursday, 9 Feb               Wednesday, 15 Feb

Run Protocol               10 days                             Thursday, 16 Feb            Wednesday, 1 Mar

Completion Report   3 days                               Thursday, 2 Mar             Monday, 6 Mar

Approval                       5 days                               Tuesday, 7 Mar               Monday, 13 Mar

Immediately you see there is a problem. Let’s look at each step in the example. Will writing a protocol really take three days? Is all the information that needs to go into the protocol available on day one? While approvals take a minimum of 10 days, the Gantt chart is only giving them five days each. If the 10-day minimum requirement is held, already the Gantt chart is off 10 days – five days for the approval of the protocol and five days for the approval of the completion report. The section pertaining to running the protocol does not reflect whether manufacturing’s operators need training on the protocol or account for extra time if the protocol fails. What if there is a material issue? Is there enough time to procure everything needed for the protocol? The step related to the completion report lacks details. Is complex and time-consuming testing required of the data collected? Do you need to send material to an outside company for analysis or specialized testing? If so, where is that time accounted for? Is statistical analysis needed that is complex and requires a lot of time?

You can see from this small example that omitted steps through a lack of experience in knowing what needs to be done can throw a Gantt chart off significantly. To avoid this type of oversight, rely upon your experienced team members. Talk to manufacturing to determine what they need to run the protocol. Will they be on shutdown? Will key manufacturing personnel be on holiday or will there be enough personnel available?

Speak to the person or persons responsible for the completion report and any analysis needed. How much time do they feel they need? Is there anything you need to be aware of when it comes to doing the data analysis? One footnote to this: Does the protocol ask for all the data needed for the analysis and in the format the analyst needs?

As for approvals, take the time to see what the approvers will be looking for. Ask team members if they have had dealings with the approvers. If so, what do they look for in approving a document? What if an approver is out traveling, sick, or on holiday? Is their backup aware of the protocol and are they willing to approve?

There are a lot of “what ifs” to think about. Of course, you can’t be paranoid and include everything, but you can be realistic about what needs to be done and what will most likely occur. Talk to other teams that have done something similar and ask them what potential setbacks or issues they ran into and see if you need to compensate for them. There is no magic formula here. It comes down to being experienced with how things work in your company and knowing the people who will be involved and what their natural tendencies may or may not be. A Gantt chart is an educated guess at the future, but you should be making honest, realistic guesses and not ones that reflect a utopian scenario.

Mistake #2: Unrealistic Timing Assigned To Project Steps

As in the above example, it is easy to underestimate timing. Often timing is entered as wishful thinking: “We’ll push them to get it done within the dates we have” or “I’ll talk to their manager to get them to focus on it.” In either case, do you realistically think that will happen? Maybe once, but every time you need something done? More often than not, their cooperation will lessen over time. You can only call in so many favors. Is there a holiday during the time you will need to execute the step? Did you account for that? One thing I’ve seen play out time after time was expecting things to get done between Thanksgiving and New Year’s Day. Believe it or not, a lot of people take days off then. In Europe, it’s not unusual for a company to shut down for an extended period between Christmas and New Year’s. Workers tend to not be as productive, either. I would tell my team that we would be lucky if anything got done during that period. Someone is out, an emergency order needs to be filled, equipment needs maintenance, etc.

Be honest and realistic with timing. If not, it may cost you dearly in the end when you need to inform management that you will miss the promised date. That usually doesn’t bode well for the project leader.

Mistake #3: Gantt Chart Is Inadequately Maintained

This seems such a simple thing to do, but so often it is relegated to an intern to update or completely forgotten. Some project leaders treat the Gantt chart as something carved in stone and refuse to accommodate changes. Often that is because they promised a date to management and it’s the project leader who will be held accountable if they do not meet the date.

Updating and adjusting a Gantt chart should be done weekly at minimum. Changes should be communicated upward. This is very important. You must keep management informed of the project status and any changes that would affect the deadline or project launch. Yes, you’ll take some heat for the changes, but if you have a solid reason for the change and explain things so they are understood, management should be understanding. If you’re lucky they may even give you more resources or help with the delay. It never hurts to be honest. Better to get it over with than to sweep things under the proverbial rug until the end. Management doesn’t like it when that happens, especially if they could have ameliorated the situation.

Another reason to keep a Gantt chart updated is to understand what has to shift or how the current issue may cascade into future tasks that might have their timing impacted. By maintaining the Gantt chart, you can see the big picture and make adjustments accordingly to minimize the “damage” to the schedule.

If you do have an intern or co-op handling the updates, be sure to check that they are capturing the adjustments properly and not causing issues themselves. Things can easily go from bad to worse through such a compounding of errors.


Gantt charts are a very effective tool, but, like any tool, it has to be used properly to be the most effective. Gantt charts are an excellent way to quickly determine the project’s critical path, seeing where your potential trouble spots are, helping to understand the tasks each team member is responsible for, and communicating the project’s progress. You maintain your car to ensure you can count on it to get you where you want to go. A Gantt chart is your project’s car. Constantly monitor and diligently maintain your Gantt chart. If you do this, your Gantt chart will become an invaluable aid in successfully completing your project.