Assumptions in Projects Are Often Neglected Risks

There are many types of risks that threaten your project. These depend on the type of project or the industry sector in which it is carried out. One particular type of risk that is often ignored, however, are the assumptions that are made in most projects. “We assume this will be the case or this will happen”. This is not only the case in projects. We also often make assumptions in our private lives. Read on and find out how you can pay more attention to this type of risk in the future.

What Are Assumptions?

Assumptions are guesses and opinions that are accepted as true or certain without proof, often without having thought critically about them. Further work and decisions in a project are then based on assumptions. If it turns out that the assumptions made are wrong, you may have to solve more or less major problems later as a result.

People are often too optimistic when making assumptions—they often assume the best case and therefore generate potential risks for the project. “We assume the law will be passed by December 2020.” However, if some politicians in parliament get in the way, then the expected law very quickly disappears into thin air and you may then have a major problem with the project. This proverb also fits in with this:

“What gets us into trouble is not what we don’t know. It’s what we assume to know that just ain’t so.”

(Mark Twain)

We Make Assumptions Every Day

In projects, we make assumptions all the time because we are often unsure about certain future conditions or events. We are also often positive about assumptions that they will happen as assumed. Here are a few simple examples:

  • We assume that parliament will approve the planned law in a month’s time
  • We assume that the project resources will be approved by the IT department
  • We assume the ordered supplier part will arrive by 11 November as promised.
  • We assume the supplier is solvent.

Assumptions Are Generally Not Bad

Assumptions can be helpful as they allow you to proceed with the planning and execution of a project, even if you do not yet have all the necessary information. However, assumptions can also entail significant risks if the assumptions are not clearly identified and managed properly.

We make assumptions every day

Assumptions Should Be an Integral Part of Your Risk Management Activities

First, you must be aware that you are making an assumption. Assumptions always contain risks. Therefore, you should include them in your risk log or in a separate list of all assumptions.

In risk identification meetings, you should also ask whether the team has made assumptions in certain situations and plan the next steps based on these.

The PMBOK® recommends that the project manager periodically checks the stability of the assumptions. This means: Are the assumptions still realistic and are they still valid? What are the consequences if the assumptions are wrong? The project team should ask itself these questions time and again.

These are typical activities when managing assumptions:

  1. Define and document assumptions: It’s essential to clearly define and document any assumption you make at the beginning or during the execution of a project. This may include assumptions about project scope, requirements, resources, deadlines, and more. By documenting these assumptions, you make them transparent to all stakeholders and team members.
  2. Identify critical assumptions: Some assumptions are more critical to project success than others. Identify these high-impact assumptions and prioritize them for further analysis and validation. Focus your efforts on mitigating the risks associated with critical assumptions.
  3. Validate assumptions: As the project progresses, work to validate your assumptions. This might involve conducting research, seeking expert opinions, or conducting experiments. The more you can validate your assumptions, the lower is their risk.
  4. Monitor and update assumptions: Project conditions can change and new information may become available. It’s essential to continuously monitor your assumptions and be willing to update them as needed. This helps ensure that your project remains on the right track.
  5. Communicate assumptions: Transparent communication is key in project management. Ensure that all stakeholders are aware of the assumptions being made and any updates or changes to them. This prevents misunderstandings and aligns expectations.
  6. Contingency planning: In your project planning, consider contingency plans for assumptions that are difficult to validate or have a high level of uncertainty. This way, you’re prepared to handle potential issues if certain assumptions don’t hold.
  7. Cross-functional collaboration: Collaborate with subject matter experts, team members, and stakeholders to gather input and insights related to assumptions. Different perspectives can help validate or challenge assumptions effectively.
  8. Assumption tracking: Use project management tools to track and manage your assumptions throughout the project lifecycle. This helps ensure that assumptions remain visible and can be easily referenced.
  9. Lessons learned: After the project is completed, conduct a post-project review to assess the accuracy of your assumptions and identify lessons learned. This information can be valuable for future projects.

Needless to say, assumptions should be an integral part of your risk management activities!


As a project manager, you should make sure that all assumptions have been identified and documented. Discussions with the project team, Stakeholder or experts provide further important input as to which other assumptions have been made and which risks are contained in the assumptions. The assumptions must be documented and continuously monitored. This is the only way to keep these uncertainties under control. For assumptions that could suddenly turn out to be invalid, contingency measures should be planned where appropriate.

Here You Can Find More Knowledge

Would you like to learn more about how to make your projects more successful with Project Risk Management? My book Project Risk Management – Practical Guide takes you an important step further!

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Posted in Risk Management.