“On time, on budget, on spec” – three constraints that often feature prominently in job postings for project managers and product managers.

The request is understandable from a management and controlling perspective; however, it’s fraught with challenges and is often unrealistic.

It is often a reality that only two out of the three pillars—being on time, on budget, or on spec—can be fully achieved, highlighting the need for adaptability and strategic decision-making.

On Spec

The issue with adhering strictly to the specified scope is that the true effort required behind that scope, no matter how meticulously defined, remains largely unknown. In many cases, these efforts are underestimated, resulting in either higher budget requirements or extended project timelines to deliver the expected scope. Uncertainties abound, beginning with the very definition of the problem or expected outcome. This underestimation can also lead to frustration among team members as they grapple with unexpected complexities.

On Time

Settling for a fixed timeframe can also pose challenges. Deadlines are not inherently detrimental; in fact, they can serve as orientation points and provide opportunities for retrospectives. However, overly rigid time constraints can stifle creativity and problem-solving, making it difficult to adapt to unforeseen circumstances and seize new opportunities for improvement.

On Budget

The budget is often a rigid constraint. However, accommodating additional or unforeseen scopes can be complex. It requires careful budget management and the ability to reallocate resources efficiently. When budget constraints are inflexible, it may lead to rushed decisions or the exclusion of valuable features, ultimately impacting the project’s quality or the product’s competitiveness in the market.


My recommendation is to maintain fixed time and budget parameters while allowing flexibility on the scope.

Why This Approach?

  • Budget Control: Keeping the budget fixed enables organizations to plan effectively. Altering budgets necessitates reallocating resources, a process that isn’t always cost-neutral due to organizational friction.

  • Goal Setting: Fixed timelines help establish defined goals. Deadlines offer guidance and opportunities for reflection. Methods like OKRs (Objectives and Key Results) can complement this approach.

  • Scope Flexibility: Allowing scope flexibility empowers teams to explore the realm of possibilities to achieve the desired outcome.

While striving for “on time, on budget, on spec” might seem ideal, it frequently proves unrealistic to attain in the realm of project and product management. Embracing a more flexible approach to scope can lead to better outcomes, enhanced adaptability, and ultimately, greater success.