Why Most Project Plans Fail in the Real World

There’s a quiet assumption baked into most project plans: if you think hard enough upfront, define everything clearly, and follow the sequence, the outcome should more or less behave. It’s neat, structured, and comforting. It’s also where things start going wrong.

Traditional planning leans heavily on what the French philosopher Henri Bergson described as geometric order. In simple terms, this is a world where cause and effect are predictable. One task leads cleanly to the next. Design flows into procurement, procurement into construction, construction into handover. It’s linear, controlled, and measurable. Most project methodologies, especially in engineering and construction, are built on this logic because, at a technical level, it works. Concrete cures in predictable ways. Loads behave according to known laws. Systems can be modelled.

But projects are not just technical systems. They are human systems layered on top of technical ones. That’s where Bergson’s second idea comes in: living order. This is the messy part. It’s the part shaped by people, changing conditions, incomplete information, and decisions made under pressure. Living order doesn’t move in straight lines. It adapts, reacts, and sometimes contradicts what was planned.

Most project plans fail because they are built almost entirely in geometric order, then executed in living order.

You see it early if you know where to look. A programme looks solid on paper, but it assumes that information will be available exactly when needed. It assumes decisions will be made on time. It assumes coordination between disciplines will happen smoothly. In reality, design information arrives late, stakeholders change their minds, site conditions differ from what was expected, and small misalignments compound into bigger issues. None of this is unusual. It’s normal.

The problem is not that planning is wrong. The problem is believing that planning can eliminate uncertainty.

There’s a tendency, especially in technically driven environments, to double down when things start slipping. More detailed schedules, tighter controls, more reporting. On the surface, it looks like better management. In practice, it often creates friction. Teams spend more time maintaining the plan than responding to reality. You end up managing the representation of the project instead of the project itself.

This is where the idea of “permanent white water,” introduced by Peter Vaill, becomes useful. He described modern organisations as operating in conditions that are constantly shifting, unpredictable, and often ill-structured. Projects don’t move from calm to chaos occasionally. They exist in varying degrees of uncertainty all the time. Some phases feel stable, others don’t, but the underlying environment never fully settles.

If you accept that, the role of a project plan changes. It stops being a fixed map and becomes more of a working hypothesis.

In practice, this means understanding when you are operating in geometric order and when you are in living order, and being able to move between the two. Early-stage planning might require broader assumptions and flexibility because information is incomplete. As the project progresses and uncertainty reduces, parts of the work can be managed more predictably. Then something unexpected happens, and you’re pushed back into living order again. This back-and-forth is not a failure of planning. It’s the reality of managing anything that involves people, time, and constraints.

Another layer to this is how people actually behave. Classical thinking assumes that stakeholders will act rationally, make decisions based on logic, and align around project goals. In reality, decisions are influenced by pressure, bias, risk perception, and personal priorities. The work of Richard H. Thaler in behavioural economics showed that people don’t consistently act in their own rational self-interest, let alone in the interest of a project (Knee, 2015). That unpredictability feeds directly into project outcomes. A delayed approval is not just a scheduling issue; it’s often a human one.

So when a project plan starts to break down, it’s rarely because the sequencing logic was completely wrong. It’s because the plan didn’t account for the dynamic environment it was placed in.

From a practical standpoint, this shifts how you approach planning and control. Instead of trying to eliminate uncertainty, the focus moves to managing it. That includes shorter planning horizons where commitments are clearer, regular updates based on actual progress, and open communication across teams. It also means recognising early when the project has shifted out of a predictable mode and adjusting accordingly, rather than forcing it back into a structure that no longer fits.

There’s also a discipline in knowing what not to over-plan. Not every detail needs to be fixed upfront, especially when conditions are still evolving. Over-specifying too early often leads to rework later. On the other hand, under-planning critical elements creates avoidable risk. The balance comes from experience, but the principle is straightforward: plan to the level of certainty you actually have, not the level you wish you had.

In environments like construction and BIM coordination, this becomes very real. A model can be perfectly coordinated at a point in time, but it represents a snapshot, not the full lifecycle of decisions still to come. Treating it as final too early leads to clashes later, not because the model was wrong, but because the environment changed.

At its core, the failure of most project plans is not a technical issue. It’s a mismatch between how we think projects should behave and how they actually behave.

The better approach is not to abandon structure, but to use it more intelligently. Geometric order gives you clarity, alignment, and measurable progress. Living order reminds you that none of that is static. The strength of a project manager lies in being able to operate in both, without becoming too attached to either.

References (APA)

• Knee, J. (2015). Review of Misbehaving: The Making of Behavioral Economics by Richard H. Thaler. Columbia Business School Publishing.

• Laufer, A. (2012). Mastering the leadership role in project management: Practices that deliver remarkable results. FT Press.

• Vaill, P. B. (1996). Learning as a way of being: Strategies for survival in a world of permanent white water. Jossey-Bass.

• Womack, J. P., & Jones, D. T. (2003). Lean thinking: Banish waste and create wealth in your corporation. Free Press.