Gantt Chart Reason#1: Finally you can see what you are doing!
Looking at a column of start and finish dates for tasks, is the primary alternative to using a
Gantt Chart.    Each row of your plan requires you to think about the dates, and position those dates in the context of preceding and dependent tasks.  This thought process, attempting to visualize your dates in your head, takes valuable thinking time, and more importantly can only be performed effectively on one or two tasks at once. A Gantt Chart enables you to see the entirety of your project plan, often on one page.  It is important that your project plan can be viewed in different timescales (daily, weekly or monthly) and can be collapsed to higher level tasks, so that you can visualize your entire project on a single page.  This visualization enables you to see new relationships between tasks, and to create new improvements in your plan.  Major timeframe improvements can be made in your Gantt Chart by identifying tasks that can be run in parallel, rather than needing to be run sequentially.

Gantt Chart Reason#2: You can communicate more effectively with stakeholders
Many high performing business people operate visually. Your Gantt chart provides a means for these people to navigate simply through a very high level of complexity in your project plan.  As the data is “visualized for them”, all stakeholders are looking at the same representation of the information.

Gantt Chart Reason#3: You can more clearly see the relationships between tasks
A key benefit of being able to visualize the relative timing of tasks, is to better understand the impacts of your plan, and better visualize relationships, which simply cannot be seen by looking at rows of data.  Your Gantt Chart should clearly identify relationships if possible as these relationships can be used to simplify and automate the management of your project.  By creating dependent relationships between tasks in your Gantt Chart, you are able to have any slippages automatically reflected throughout the plan.

Gantt Chart Reason#4: You can see ahead…for miles
A good
gantt chart tool will enable you to plan well in advance.  Sometimes visualizing longer term plans can feed back to changing your short term plans.  A good gantt chart should let you plan at least 10 years in advance, however be able to change your view so that the entire planning range can be visualized on one page.

Gantt Chart Reason#5: You can identify resource clashes
Using a Gantt Chart, you can easily see periods when a resource is scheduled on multiple tasks.  If this scheduling is a full time allocation to each task, then something as to give.  A gantt chart enables you to see these emerging issues in advance and take evasive action, otherwise known as project management.