Gantt Chart

A Gantt chart is a visual scheduling tool that represents a project's tasks, durations, and dependencies as horizontal bars on a timeline. Each bar corresponds to a task or milestone, positioned to show when it starts and when it finishes. Developed in the early 20th century by mechanical engineer Henry Gantt, the format has become one of the most widely used planning tools in construction, project management, event production, and operational businesses of all sizes. The core value is clarity: anyone looking at a Gantt chart can immediately see what is happening, when, and in what sequence.

How a Gantt Chart Works

A Gantt chart divides a project into individual tasks or phases listed vertically on the left. A horizontal timeline runs across the top - typically days, weeks, or months depending on project length. For each task, a bar extends from its start date to its end date. When two tasks are linked - where task B cannot begin until task A is complete - an arrow shows the dependency between them. The result is a visual map of the whole project on a single page.

Most Gantt charts also show milestones (key dates or deliverables, usually marked with a flag), a baseline versus actual comparison (how planned dates compare to where the project actually stands), resource assignments showing who is responsible for each task, and the critical path - the sequence of tasks where any delay will push back the project completion date.

Where Gantt Charts Are Used in Practice

Gantt charts are standard in construction project programmes, where a contractor needs to coordinate multiple trades across a phased schedule. An electrical contractor might use one to plan first fix, second fix, testing, and certification phases so that each trade knows when to be on site and suppliers know when to deliver.

In office furniture and interior projects, Gantt charts help dealers and workspace designers track manufacturing lead times from multiple suppliers, coordinate delivery windows, and schedule installation crews across a multi-room or multi-floor project. The chair order might need to arrive two weeks before the desks because installation sequencing requires it - and the Gantt chart makes that dependency visible.

AV systems integrators use Gantt charts to programme site access, rack builds, cable runs, and commissioning stages. Renewable energy installers use them to align survey, DNO application, equipment delivery, and installation crew scheduling across multiple jobs running simultaneously.

Gantt Charts vs Other Scheduling Formats

A task list shows what needs doing but not when. A critical path network shows dependencies in detail but can be difficult to read quickly. A Gantt chart sits between the two: it shows sequence and timing together in a format that both project managers and clients can understand without specialist training.

For shorter projects - a single-room fit-out or a two-day installation - a Gantt chart may add more structure than the job needs. For anything running longer than a week with multiple people or suppliers involved, it is the standard tool for keeping everyone aligned on dates, dependencies, and progress.

Zigaflow's project tracking features allow businesses to set milestones, assign responsibilities, and monitor progress across active jobs without switching to a separate scheduling tool.