Gantt Chart Planning

Origin. Adamiecki's harmonogram (1896); Gantt (1910s).

Mechanism. Represents tasks as bars on a time axis with dependency links, making the critical path and the resource conflicts visible simultaneously.

Procedure. Decompose to tasks. Estimate durations. Establish dependencies. Compute the critical path — the longest dependency chain, which is the schedule. Identify slack elsewhere. Load-check resources against the bars.

Applies to. Projects with well-understood tasks and stable dependencies.

Limitations. Encodes point estimates for durations that are distributions. Because the project duration is the maximum over parallel paths, and the expected maximum exceeds the maximum of the expectations, a Gantt chart built from mean durations is biased optimistic by construction, and increasingly so with parallelism. This is Jensen's inequality, not pessimism.