Based on the workload, you can categorize resources into Resource Over-Utilized, Resource Under-Utilized and Resource Optimally Utilized.
Multiple bars against a resource for the same time period indicate that the resource is over-utilized. So you can allocate one of the tasks to other resources or reschedule to some other time. For over-utilized resources, a red badge is displayed with additional workload (overloaded hours) in the upper-left corner of the corresponding date/week. On hover over the badge, the operational hours of that resource, total hours allocated, and additional hours allocated to that resource will be displayed.
A bar with unutilized time against a resource indicates that the resource is under-utilized. You can assign tasks to that resource in the unutilized time period. For under-utilized resources, a blue badge is displayed with unutilized hours in the upper-left corner of the corresponding date.
A bar without unutilized time against a resource indicates that the resource is optimally utilized.