Gantt chart: A guide to optimising your project
As a project manager, you need to know how best to use the time available for the project. For this reason, time planning is carried out and an attempt is made to simply present time-relevant facts to the project participants through visualisation. In concrete terms, this means finding out how much time is needed for certain tasks or which time constraints have to be observed. Dependencies between different tasks should also be recognized and taken into account accordingly. The Gantt chart proves to be an extremely useful tool for getting the most out of time planning and visualisation, conveying more in one powerful image than a thousand words can express.
Basics of a Gantt chart and its components
Create a Gantt chart: step-by-step guide
Step 1: Define the task list
To create a Gantt chart, you must first define your task list, which contains all the tasks necessary to complete your project. You can either take these tasks directly from the Work Breakdown Structure as work packages or derive them from work packages. It is important to have a short description for each task to get a complete picture of the project.
Step 2: Determine the duration of each task
The next step is to determine the duration of each task. If the task is a work package, you can get the information directly from the work package description. For all other tasks, you need to make a realistic estimate to ensure that the chart is meaningful later. It is recommended to do the estimation in a team to ensure higher accuracy.
Step 3: Determine the dependencies
Once you have determined the duration of each task, you need to identify the dependencies between the tasks. Determine the order in which the tasks must be completed and highlight the tasks that are dependent on each other.
Step 4: Create a schedule
To continue creating the Gantt chart, draw a horizontal axis representing the time period of your project. The vertical axis contains the task list. For each task, draw a horizontal bar representing its duration. Each unit on the horizontal axis corresponds to a certain period of time, e.g. one week. For example, if a task takes 4 weeks, the bar should be 4 units long. Milestones marking important events in the project can be marked with a triangle in the week they are due.
Step 5: Add dependencies
You can use arrows to show the dependencies between tasks. If one task depends on another, simply draw an arrow line from the task to be done first to the second. This visually shows the relationship between the tasks and makes it clear which tasks need to be done first in order to proceed with others.
Step 6: Label the diagram
Give each task and the whole project a name. Also indicate the start and end date of the project. Do not forget to label the axes. Make sure the diagram is easy to read and understand and add colours to make it even clearer.
Step 7: Keep the chart up to date
Keep the Gantt chart up to date by reviewing it regularly and updating it as needed. Changes to tasks and dependencies need to be reflected in the chart to keep it meaningful and useful.
Common mistakes to avoid when creating and using Gantt charts include
Mistake number 1
The first major mistake often made by inexperienced project managers is to equate the Gantt chart with project management and start the project by creating the project plan. However, caution is needed here. The Gantt chart is only a project management tool, and it requires skilled groundwork to use it properly. If this is taken into account, the project can benefit from the support of the Gantt chart.
Mistake number 2
The second big mistake is that the Gantt chart is created virtually "off the cuff" without knowing exactly what it is about. In this respect, the following should be noted: The Gantt chart is based on work packages that have to be summarised in a Work Breakdown Structure (WBS). However, in order to be able to create a WBS, it must be possible to refer back to the project goal definition and the specification of the service to be provided. So if neither a goal formulation incl. specification nor a WBS with the relevant work packages is available, the Gantt chart will not work because the individual tasks and also their interdependencies cannot be understood correctly.
Mistake number 3
The third mistake is that project managers think they can work on the Gantt chart alone behind closed doors. This is not advisable. The recording of the work packages relevant to the project and their technical design, the so-called work package description, requires the cooperation of qualified team members in every project. As is so often the case in project work, teamwork is also important for the Gantt chart.
The Gantt chart in project planning and task tracking
Gantt chart in combination with other project management areas
In addition to activities and tasks, the Gantt chart can also show outstanding events - milestones - in the course of the project. A milestone is an event of special significance in the course of a project, such as the completion of a phase or the completion of a subtask. Unlike activities, milestones are dimensionless and do not require time. The Gantt chart extended by milestones forms the basis for the milestone trend analysis (MTA), another important instrument of project management. With the MTA, the milestones are systematically observed and their shift in the course of the project is shown. From the shifting of milestones, conclusions can be drawn about schedule deviations and important corrective and supplementary adjustments can be made in the project.
The Gantt chart can also be helpful for resource management. In the project, resources, i.e. personnel or material resources, are needed to realise work packages, for example. The task of resource management is to determine the required resources, to assign them to the individual activities in the project and to monitor and control their effective use. With the aim of being able to assign a suitable resource to each resource requirement, the resource plan provides an overview of the available or required resources. By assigning the required resources to operations, which in turn are linked to the time axis in the Gantt chart, the resource requirements can be identified, planned and controlled.
In the Gantt chart, the critical path, i.e., the longest and thus time-determining chain of operations, can be shown directly in the flowchart. The critical resources are the bottleneck resources used on the critical path, which can be derived indirectly from the Gantt chart. The Gantt chart is also suitable for identifying project risks, which are then subjected to a concrete risk analysis and assessment as part of risk management.