Automatic scheduling

Let Celoxis take care of the schedule

With auto scheduling, Celoxis computes the start and end dates for each task from the task owners (resources) work timings, holidays, effort, dependencies and constraints. 

The essence of automatic scheduling is governed by a simple formula:

Before, we understand the equation, let us understand the variables involved:  

Work or Effort:

Work is the amount of effort ( independent of a resource) required to complete the task. Typically it is described in man-hours. Effort indicated is irrespective of holidays and resources since not all resources may be working equal hours.
 

Duration:

Duration is the length of working time between the start and finish of a task. The working time for a task is defined by the project and resource calendars. For example, If today is Monday and you say "I want this report by Friday" you are indicating a duration. It does not mean that the resource must spend all their time to prepare the report. The actual report preparation may take only 5 hours. In this case 5 hours is the effort but the duration is 5 days assuming that there are no holidays in between. 
 

Units:

Resource units indicate how much of a resource's available time, according to their work calendar, is being used to work on a particular task. Allocation is a way to have a resource work on multiple activities at the same time. It can be specified as a percentage of daily working time or as a total number of hours that a resource must spend on the task.

For example, if a resource works 8 hour every day and you allocate that resource for 50% on a task, you are effectively saying - spend 4 hours on that task daily. On the other hand if you enter allocation in hours it indicates that the resource should work a total of those hours on a task. 
 

Let's see some examples so see how it works. For all these examples, assume that the 1 Man-day = 8 hours and all resources also work 8 hours per day.

A task requires 16 hours effort to finish and you assign a resource to work full time (i.e 8 hours per day). How long would it take to complete the task? If you said 2 days, you are right. Let's see if the equation matches with our expectation. In this case, effort = 16 hours and resource allocation is 1 (i.e 100%). So duration = 16 ÷ 1 = 16 hours or 2 days since each day is 8 hours.

Now assume that you add one more resource to the task. How long would it take to finish the task? Again, it's quite easy - 1 day. Both resources will work 8 hours each and finish the 16 hour task in a day. Let's see again if the equation matches with our expectation. In this case, effort remains 16 hours while allocation is 1 + 1 = 2. So duration = 16 ÷ 2 = 8 hours or 1 day. Now let's make it a bit harder. If both resources are told to work only 2 hours per day i.e 25%, then how long would it take? Effort remains 16 hours while allocation is now 0.25 + 0.25 = 0.5. So duration = 16 ÷ 0.5 = 32 hours i.e. 4 working days.

To get the most out of scheduling, you need to understand and effectively use all three parts of the scheduling formula: W = D * U. You can control which of the scheduling formula parameter has the most influence over the task's scheduling. 
 

There are many other factors that Celoxis takes into consideration while scheduling a task. Let us look at them.