The Gantt Chart is a business management tool used by managers to plan and schedule projects, and monitor their progress.
Effective project management allows managers to complete a project successfully in the quickest time available by overseeing at the same time a large number of activities and ensuring that each task is completed in full and on schedule.
The Gantt Chart in details
The Gantt Chart shows clearly all the tasks in a particular project plotted against the timescale indicating exactly when each task will start and finish, and how much time (in days, week or months) each task will take to be accomplished. The Gantt Chart shows this information visually giving project managers an constant overview of the entire project lifetime, all the activities involved with duration, when each individual activity needs to be finished, and if there are any delays.
In practice, The Gantt Chart can help supervisors see whether factory workers were on target in meeting deadlines for manufactured output.
Benefits of Gantt Charts
The ultimate purpose of producing The Gantt Chart is to identify the shortest amount of time needed to complete the entire project. This requires that the various tasks of a project are planned in a logical order. All these tasks must be completed with minimal delay and maximum efficiency. While some of the tasks can start at the same time other tasks cannot start until proceeding tasks (the task(s) coming before) are successfully finished.
If a deadline of one task is missed, it means that very likely there will be delays for the rest of the project. And, late completion of the entire project, or the late delivery of output to a client, can be very costly to the business. It may result in fines and penalties as stated in the contract, loss of sales revenue as products are not being sold to clients or even loss of customer loyalty in the long-term.
How to construct The Gantt Chart?
Today, to generate Gantt Charts, project managers use computer software such as Microsoft Project, Microsoft Excel spreadsheet or GanttPRO for online project management.
Nevertheless, let’s take a look at basic rules used to construct and interpret Gantt Charts, in case you need to construct your Gantt Chart manually.
To start with, The Gantt Chart is presented as a bar chart showing all the scheduled tasks over a given time scale. The time scale is almost always shown on the horizontal axis.
Each activity is shown by a separate horizontal rectangular bar with the length depicting the duration of the activity. Usually, different tasks (bars) will be using different colors. Each bar will also include the start date, duration and end date of a task.
This is a short instruction how to construct a simple Gantt Chart:
1. Break down the project into separate and clearly identifiable tasks.
2. Identify all the tasks required for the completion of the project.
3. Determine how long each of these tasks will take (in days, weeks or months).
4. Identify all dependencies. Dependencies are activities which cannot start until the completion of other tasks.
5. Determine which tasks can take place at the same to in order to minimize the duration of the whole project.
6. Place all tasks in the right sequence on your Gantt Chart.
Both critical and non-critical activities must be shown. Critical activities cannot be delayed. Non-critical activities will have some slack time (they can start earlier or later without delaying the whole project).
Predecessor-successor relationships must also be shown – activities that must be preceded by others and activities that must follow others.
Examples of Gantt Charts
The beginning and end date for the following project Recruiting a new employee in Example A have already been set. As you will notice, without using The Gantt Chart, all individual tasks counted will amount to more days required to complete this project. Therefore, with The Gantt Chart we are able to reduce duration of the whole project which results in cost-saving benefits.
Example A: Recruiting a new employee
This is a real-life example of the project where the Human Resources department is hiring a new employee. It was published by Boston University Medical Campus.
All tasks amount to 30 working days according to Duration (in days). However, The Gantt Chart shows that the duration of this project can be reduced to 28 working days, therefore saving 2 working days.
Task 1 ‘Agree job and person specification’ takes 1 working day to complete. So, the earliest Task 2 ‘Personnel manager to define job grade’ and Task 3 ‘Prepare advertisement’ can start after Day 1.
Task 2 ‘Personnel manager to define job grade’ lasts for 5 working days, so Task 4 ‘Publish advertisement on the website’ cannot start until Day 7, right after Task 2 ‘Personnel manager to define job grade’ is completed.
Task 5 ‘Receive enquiries and send further information’ can only start after Task 4 ‘Publish advertisement on the website’ is successfully finished.
Task 7 ‘Agree composition of interview panel’ can take place at the same time as both Task 2 ‘Personnel manager to define job grade’ and Task 3 ‘Prepare advertisement’.
Although Task 7 ‘Agree composition of interview panel’ can be finished by Day 4, Task 9 ‘Evaluate applications and prepare shortlist’ cannot start until Task 5 ‘Receive enquiries and send further information’ is also finished. Finishing both Task 5 ‘Receive enquiries and send further information’ and Task 7 ‘Agree composition of interview panel’ is required to start Task 9 ‘Evaluate applications and prepare shortlist’. Completion of Task 7 ‘Agree composition of interview panel’ and Task 8 ‘Book interview room’ can be delayed by 12 days without there being a delay to the overall project.
But, Task 8 ‘Book interview room’ can only start after Task 7 ‘Agree composition of interview panel’ is accomplished. It is because realistically, we need to know how many people are on the interview panel in order to prepare the interview room of the proper size.
As mentioned earlier, only after Task 5 ‘Receive enquiries and send further information’ is over, we can start Task 9 ‘Evaluate applications and prepare shortlist’. Task 9 will take 3 days.
Task 10 ‘Invite shortlisted applicants for interview’ takes only 1 working day, but we need to wait additional 4 working to receive confirmations from shortlisted applicants that they will in fact participate in the interview.
Task 11 ‘Conduct interviews’ takes 1 day. It will happen on Day 26.
Task 12 ‘Confirm selection decision’ will take place on Day 27 immediately after Task 11 ‘Conduct interviews’ is completed.
Task 13 ‘Send the offer letter to successful candidate’ takes a further 1 day, so the shortest time necessary to complete this project is 28 working days.
Other examples of projects include baking a birthday cake, starting up a new business, constructing a bridge, writing a research paper, building a house or decorating a new office.
