PMP lesson · Schedule · Schedule · lesson 4 of 4 · about 6 minutes

Resource levelling vs resource smoothing

Predictive · hybridFree preview

Goal: After this lesson you can explain the difference between levelling and smoothing, and predict what each does to the end date and the critical path.

1The situation

Four welders on a two-welder team

The robot cell schedule looks fine on paper: 10 days. But on days 3 and 4 it needs four welders, and the company has only two.

You have two choices: move work so that no day needs more than two welders, even if the project gets longer, or only move work inside its float so that the end date stays the same, accepting that some peaks may remain.

These are resource levelling and resource smoothing.

2Two ways to fix resource problems

Both start from a resource histogram: a bar chart showing how many people are needed each day.

Levelling

Respect the limit

Moves work until no day exceeds the available resources. The end date can move and the critical path can change.

Smoothing

Stay within float

Moves work only within float. The end date does not move; some over-allocation may remain.

Exam shortcut: “end date cannot change” → smoothing. “limited resources, date may move” → levelling.

3See it in one picture

Before: days 3–5 need more welders than available (red). After levelling: never more than 2, but the work takes longer.

4How it looks on the exam

Exam-style question 1. The customer will not accept any change to the go-live date. The resource histogram shows that two electricians are over-allocated during week 6, and some of their activities have float. Which technique should the project manager use?

A. Resource levelling

B. Resource smoothing

C. Fast tracking

D. Crashing

Show the answer and the decode

Answer: B.

In simple English

Too much work for the electricians in one week, but the date cannot move.

What is the question really asking?

The right technique.

Key words / trigger

“will not accept any change to the go-live date … have float”

PMP logic

Smoothing moves work within float without changing the end date.

Why the wrong answer looks attractive

Levelling also fixes over-allocation, but it may delay the project.

5Remember this

Your memory card

Levelling = respect resource limits; end date and critical path can change
Smoothing = even out usage within float; end date does not change
Start from the resource histogram
After levelling: recheck the critical path; baseline changes go through change control

The full lesson in the PMCLEAR app also has:

the rest of the lesson (What happens after levelling)
a worked example
the common traps (wrong vs right)
2 exam-style questions with the decode
a 3-question quick check

Open the full lesson → Create a free account

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