How should you create a Gantt Chart

Published by Massimoluigi Casinelli on

A Gantt chart is the best known and simple tool used in project management; beginners tend to develop the Gantt chart too simplistically. By adopting some project management “techniques”, we can develop a more robust and meaningful Gantt chart for project planning purposes.

Gantt chart can be used to assign tasks to a project team or as a high level schedule, prepared, for example, at Pre-planning stage. Gantt chart is adopted usually to illustrate a summary schedule at planning stage or during project execution, to summarize detailed large schedule: a summary schedule in the format of a Gantt chart serves as a road map. 

At planning stage, when you need to develop the project schedule by a Gantt chart, you should first develop a WBS to identify and break down the scope of work, until the identification of the so called “work packages” (WP), which are manageable entities, as they can easily planned, associated to specific deliverable(s) and assigned to a unique responsibility. The WP can become the single activities of your Gantt Chart, even if a WP may contains further detailed tasks.

Once you have identified the single activities of your Programme (i.e. Schedule) you may list them. Then, you need to estimate the expected duration of each activity, a start date and a finish date. You can prepare this on a table (Excel) and, finally, transferring it on the Gantt chart. There are many predefined templates developed for Excel, in case you don’t want use a Schedule software, but you should definitely use it, at least for professional applications.

In the figure above, there are shown also “milestones”, on the top rows of the chart. The “red flags” are key dates that must be achieved in the project execution (other terms are into Italian language, but the scheme is pretty clear).

As you probably know, the Gantt chart can be developed when you have a clear understanding of the process, i. e. the sequence of the work that must be carried out.

Planning and scheduling are two separate processes.

However, be aware that Gantt chart doesn’t show clearly the “logic”, neither the sequence of the activities. By using only a Gantt chart, you will not be able to analyze the “critical path”. On the converse, if you first develop the “logic network“, which represents the “process “to be followed in execution the project, you will get a much robust Gantt chart, on the base of a clear sequenced process; in fact, planning and scheduling are two separate processes.


The most effective way to develop a Gantt chart is starting from planning first, by developing the WBS to identify the WPs and the proper “planning level” for scheduling the “works”. Then, you have to develop the processes, by building a logic network; finally you can produce the Gantt chart. A software tool will give you a tangible advantage, see the figures below obtained with an advanced tool (P6), showing the logic network and the Gantt chart.

Logic network vs. WBS
Gantt chart obtained by a CPM

If you are not familiar with planning and scheduling techniques, it would be appropriate following a basic course on planning and scheduling or studying the topic. There are few key concepts, not particularly difficult like the critical path method (CPM), that you should understand properly in order to develop plans and related schedules.

Learning planning and scheduling

If you wish to become a professional project planner, you need extending your knowledge, by mastering other topics like: working with multi-calendars, schedule constrains, longest, critical and sub-critical paths, float optimization, resources leveling (see the resource histograms into the figures above), schedule design and organization. There are further specializing topics to master, in order to become an expert in specific fields like: QSRA (quantitative schedule risk analysis), forensic planning and schedule delay techniques.

I offer advanced training courses in such as topics . Contact me for further information.

Categories: Short notes

Massimoluigi Casinelli

I am a chartered civil engineer and certified CCP (cost engineering and total cost management) at AACE International, with thirty years of experience in project management of the construction sector. I deliver expert planning, programme management and project controls on multibillions-Euro infrastructure programmes, including highways and railways, metro, air terminals and complex buildings (commercial, residential, schools), with some experience in oil & gas and power. I worked in advanced contexts of project management (from matrix organizations of EPC contractors to large employers organized to manage complex capital projects), by undertaking various roles in the field of project management / controls and contract management; this diverse range of experiences allowed me to gain knowledge on the various components of project controls (schedule, cost estimating, budgeting and cost control, progress and performance measurement, risk and claim management). I am an Italian citizen, currently in Italy.

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