--- title: "Gantt chart: what it is and how to read one | attendo" description: "What a Gantt chart is, how to read its bars and dependencies, a project example, what it does not tell you and the mistake of never updating it after day one." url: "https://attendo.me/en/glossary/gantt-chart" lang: "en" --- # Gantt chart: what it is and how to read one Also known as: Project timeline · schedule chart A Gantt chart is a project schedule drawn as bars: each task takes one row, and its bar starts and ends on its planned dates. ## How to read it - **The rows** are the tasks or jobs, often grouped into phases. - **The horizontal axis** is time: days, weeks or months. - **The length of each bar** is that task’s planned duration. - **The arrows** between bars are the [dependencies](https://attendo.me/en/glossary/task-dependencies): what cannot start until something else finishes. ## An example Remodeling a store: demolition from the 3rd to the 7th, electrical and plumbing from the 10th to the 21st, painting from the 24th to the 28th. If electrical and plumbing slip a week, the Gantt chart shows at once that painting moves with them, and so does the handover. ## What a Gantt chart does not tell you Whether there are people to do it. A Gantt chart can look perfect and be impossible, because the same person appears on three bars at once. That is why you read it alongside [resource utilization](https://attendo.me/en/glossary/resource-utilization). ## The usual mistake Drawing it once and never touching it again. A Gantt chart that does not reflect what happens is a picture of day one. And without a saved [baseline](https://attendo.me/en/glossary/project-baseline), when dates move there is nothing to compare them with. ## In attendo The [attendo Gantt chart](https://attendo.me/en/modules/gantt-chart) breaks each project into phases, line items and documents, with dependencies and a baseline. Progress comes from the documents your team closes, not from someone updating it by hand. - [attendo Projects](https://attendo.me/en/projects) ## Where it is used in attendo ### Modules - [Gantt chart](https://attendo.me/en/modules/gantt-chart): Plan projects and construction jobs with dependencies and a baseline - [Projects and construction](https://attendo.me/en/modules/projects): Jobs and plant shutdowns with line items, progress and live cost - [Scheduling and calendar](https://attendo.me/en/modules/calendar): The team’s schedule, based on each person’s real working hours ### Industries that use these modules - [Energy and renewables](https://attendo.me/en/industries/energy-renewables) - [Contractors, construction and engineering](https://attendo.me/en/industries/contractors) - [Consulting and professional services](https://attendo.me/en/industries/professional-services) - [HVAC and refrigeration](https://attendo.me/en/industries/hvac) - [And any other business](https://attendo.me/en/industries) ## Related terms Projects ### Baseline Project baseline · schedule baseline A baseline is the saved copy of a project’s approved plan, with its dates and durations. It lets you compare what was planned with what is actually happening at any time. Projects ### Task dependencies Finish-to-start · predecessors Task dependencies are the rules that tie the start or finish of one task to another, such as painting not starting until the plaster has dried. Projects ### Resource utilization Team workload · utilization rate Resource utilization is the share of each person’s available hours that is already committed to planned work, measured by day, week or month. ### On the blog #### Project baseline: spot the drift while you can still fix it Almost every project drifts. The problem is finding out at the wrap-up meeting, when there is nothing left to fix. A baseline lets you see it in week two, not in the final week. 4 min read [See all 53 glossary terms](https://attendo.me/en/glossary) ## Shall we look at it with your data? We will show you how what you just read works in attendo, with your own assets, tickets and customers. If it is not a fit, we will tell you. - With your operation, not a generic demo - A real person from our team replies - No cold calls afterwards Would you rather talk first? - Phone [+34 910 053 530](tel:+34910053530) - Email [sales@attendo.me](mailto:sales@attendo.me) - Monday to Thursday 9:30 AM to 6:30 PM and Friday 9:30 AM to 2:30 PM (Spain time)