Making Assumptions Work for Your Project: A Structured Approach for Project Controls

When it comes to managing projects, where uncertainty is often the norm, assumptions play a vital role in bridging knowledge gaps and facilitating progress. According to PMI, PMBOK Guide 7th Edition, Assumption is “a factor in the planning process that is considered to be true, real, or certain, without proof or demonstration.”

As a project controls professional, it's imperative to understand that assumptions, though sometimes necessary, introduce risk and uncertainty to the project. As a result, effectively managing assumptions becomes crucial for project success, particularly in interconnected areas like planning, scheduling, cost and risk management.

This article explores a structured process for identifying, documenting, validating, and managing assumptions within the construction environment, ensuring that they contribute to informed decision-making rather than becoming a source of disruption.

The Importance of Assumptions in Project Controls

Throughout a project's lifecycle, many variables remain uncertain—especially during early stages and periods of significant changes. It’s common for construction projects to face uncertainties related to resource availability, weather conditions, regulatory approvals, or even project funding. These gaps are often filled with assumptions that provide a basis for project scheduling, budgeting, and resource allocation to move forward.

For example, we may assume that a subcontractor will deliver a critical component by a specific date, that regulatory permits will be approved without delay, or that design packages will be approved/certified in their first review cycle. While these assumptions allow the project to progress, failure to manage them effectively can lead to missed deadlines, cost overruns, or resource shortages. That's why assumption management is a key component of project controls.

1. Identify Assumptions Early

Assumptions should be identified as early as possible during the project initiation and planning phases. Working closely with key stakeholders—including clients, team members, and subject matter experts—helps uncover areas of uncertainty. Some examples of critical areas where assumptions commonly occur are:

• Resources: Will key personnel or equipment be available when needed?

• Duration: Are task durations based on historical data or assumptions about productivity?

• Cost: What assumptions are being made about rates, quantities, and price escalation?

• External Dependencies: Are you relying on third-party approvals or the timely delivery of materials?

• Contractual Requirements: Are there gaps or ambiguities in contract clauses and requirements that require assumptions to proceed? Have all contract-specified assumptions, such as Access Dates, Site Possession dates, and Interface Milestones, been identified?

  
  

It's also important to balance the effort spent identifying assumptions against potential benefits. While assumption identification is crucial, spending excessive time trying to uncover every possible assumption can reduce the process’s agility and effectiveness. Instead, focus should be on identifying assumptions that could significantly impact project success.

2. Document Assumptions in Detail

Once assumptions are identified, it's crucial to document them in an Assumption Log, which serves as a living document tracking all assumptions throughout the project's lifecycle.

This document should be readily accessible to the entire project team and regularly updated. Key details to include in the log are:

• ID: A unique identifier for the assumption

• Assumption: A clear description of what is being assumed

• Category: The type of assumption (e.g., Resource-Related, External Dependencies, etc)

• Date Identified: When the assumption was first logged

• Owner: The person responsible for the assumption

• Validation Status: Current state of validation (Pending/Validated)

• Validated By: Who confirmed the assumption

• Potential Risk: Impact if the assumption proves to be incorrect or invalid

• Risk Owner: The person responsible for managing the risk

• Mitigation Plan: Steps to address potential assumption failure

  
  

Documenting assumptions creates transparency and ensures that the project team understands what factors were considered when establishing the project's schedule, cost, and risk profile.

While this list is comprehensive, project teams should evaluate which fields are most relevant to their specific needs. For instance, smaller projects might focus on just the assumption description, owner, and validation status, while complex projects might require tracking all these elements.

The key is to maintain a level of detail that adds value without creating unnecessary administrative burden.

3. Validate Assumptions Where Possible

Validating assumptions is crucial as it strengthens our confidence in their accuracy, which in turn reduces project’s exposure to risk. Whenever possible, assumptions should be validated through data, expert consultation, or testing. For example, if assuming a task would take two weeks, reviewing historical project data could verify if this estimate was realistic. For complex technical assumptions, engaging subject matter experts could provide insight into whether assumptions were reasonable.

Validation efforts should be documented, noting which assumptions had been confirmed as valid and which remained pending validation.

4. Use Assumptions as Input for Risk Management

Every assumption carries an inherent level of uncertainty and potential risk to the project. By integrating the process of management assumptions with the risk management process, project teams can better understand and prepare for potential threats and explore opportunities. The Assumption Log thus becomes an essential tool that enables teams to:

• Improve identification of project risks and the development of the project's risk register

• Determine potential impacts on project objectives if the assumption proves incorrect

• Simulate scenarios using different assumptions

• Enhance duration uncertainty evaluation in the project schedule

• Develop appropriate risk responses and controls

This integration ensures that assumptions don't exist in isolation but are part of a comprehensive project controls framework that enhances decision-making and reduces uncertainty.

5. Communicate Assumptions Transparently

Clear communication becomes critical when dealing with assumptions. Ensuring that assumptions are communicated to all relevant stakeholders—whether internal team members, clients, or external contractors—helps everyone understand the risks associated with assumptions and enables them to contribute to managing them effectively.

Incorporating assumptions into key project documents—such as the Basis of Schedule (or Program Narrative), Cost Estimates, and Management Plans—provides transparency and helps prevent misunderstandings later in the project.

6. Monitor and Review Assumptions Regularly

Assumptions are dynamic and evolve throughout the project. As new information becomes available, the project team must regularly review and validate these assumptions. This continuous monitoring ensures the project stays aligned with current conditions and remains on track.

7. Lessons Learned

Conducting regular lessons-learned sessions throughout the project, not just at its conclusion, is essential. This helps the team reflect on which assumptions proved correct, which did not, and what the impact was. Such analysis not only provides insights for improving the overall project management level of maturity but also helps refine assumption management techniques, making future projects more resilient.

Conclusion

Assumptions are an unavoidable part of Project Controls and must be managed systematically. Through a structured process of identifying, documenting, validating, and monitoring assumptions, project teams can reduce uncertainty, mitigate risks, and improve decision-making.

When carefully managed, assumptions enhance project reliability, minimize disruptions, and lead to better outcomes. In project controls, where data-driven insights and predictive capabilities are essential, making assumptions work for you, rather than against you, is key to achieving project success.