Every project is subject to some uncertainty, but the amount of uncertainty can vary.

Knowing a project’s uncertainty profile — ranging from simple variation to outright chaos — will help choose the right management strategy.

There are four uncertainty profiles along a spectrum:

Variation
Foreseen Uncertainty
Unforeseen Uncertainty
Chaos

Where the project goal is clearly known and defined at the outset, as well as the solution or route for getting to it, it is very best suited for the application of what is commonly thought of as ‘traditional’ project management -

define the objective
make a plan to get there
execute the plan
monitor how well we are executing against the agreed the plan
course correct to bring as close as possible to the plan

Characteristics of a Project with Variation

All parties agree on what needs to be built and how the solution meets the objective.
The team understands the tasks, their duration, dependencies, and potential pitfalls.
Similar projects have been completed before, ideally by the same team. Even if not, if proven approaches and replicable information exist, uncertainty remains low.

Examples Include

Office Fit-Out - Designing and furnishing a standard office space using established layouts and suppliers.

ERP System Upgrade - Applying a vendor-recommended upgrade path for an existing system with minimal customisation.

Road Resurfacing: Routine maintenance using proven methods and materials.

The Project Manager’s Role

In variation-driven projects, the project manager acts primarily as a troubleshooter. The focus is on identifying deviations and applying corrective measures to keep the project on track. Radical changes to scope or approach are rare; the challenge lies in controlling slippage in budget, schedule, and deliverables.

Project Setup

Plan for variation by building in buffers — tolerance, contingency, capacity, and budget reserves.
Divide schedules into phases and add contingency buffers to each phase and budget line.
Protect buffers: they are not bargaining chips. Success includes staying within tolerance, even if cushions are used.
Set baselines before starting; without them, monitoring is meaningless.
Perform critical path analysis to identify tasks that most affect timelines and prioritise accordingly.

If variation is ignored during planning, the project manager will end up firefighting — wasting resources and draining stakeholder confidence.

Monitoring and Decision-Making

Once baselines and buffers are in place:

Track performance variables (e.g., schedule variance, cost variance).
If deviations stay within tolerance, no action is needed.
If they exceed thresholds, act quickly — shift suppliers, expedite subcontractors, or adjust delivery dates.
Reserve senior leaders for major deviations, not minor course corrections.

Key Techniques

Add contingency and reserves to schedule and budget.
Set baselines before project start.
Perform critical path analysis.
Define acceptable tolerance and empower the project manager to act within it.
Establish monitoring procedures and data points (e.g., burndown charts, cost/time performance).
Maintain strict scope control to prevent uncontrolled variation.

References

DE MEYER, Arnoud; LOCH, Christoph H.; and PICH, Michael T. (2002). Managing project uncertainty: From variation to chaos. MIT Sloan Management Review. 43, (2), pp.60-67.
MONTEIRO MARINHO, Marcelo Luiz; DE BARROS SAMPAIO, Suzana Cândido; DE ANDRADE LIMA, Telma Lúcia; DE MOURA, Hermano Perrelli (2015). Uncertainty Management in Software Projects. Journal of Software. 10, (3), pp.288-303.

Managing a project with limited uncertainty