P6 Professional has an automatic schedule option, which is good. The question becomes when to schedule automatically and when not to.
P6 Professional defaults to non-automatic scheduling. When turned on, the automatic scheduling option is an efficient way to see the effect of schedule changes quickly. Figures 1a and 1b show the number of clicks required to schedule a project in schedule non-automatic mode.
Figure 1a
Figure 1b
As demonstrated, you need at least four mouse clicks when the same data date (or status date) is used for the scheduled operation. This can become a repeated laborious process and a drag on efficiency when you want to see the outcome quickly. You could bypass steps one and two by tapping the function key, schedule (F9), to bring up the schedule dialog. Learn about P6 Professional Hot Key Commands.
The hotkeys minimize clicks. But automatic scheduling requires zero clicks and no hotkey typing, which is hard to beat. Then why not always set the automatic scheduling option on? There are operations when it is best to have this option off.
This article discusses and recommends when and when not to schedule automatically in P6 Professional.
Let us use the following project schedule for our discussion, Figure 2.
Figure 2
The automatic scheduling toggle option is found by clicking Tools | Schedule and Options, Figure 3.
Figure 3
Then, in the Schedule options dialog, toggle on or off “Schedule automatically when a change affects dates” Figure 4.
Figure 4
Schedule automatically provides an operative advantage for (1) project planning, (2) scope changes, and (3) schedule compression efforts.
The following is an inexhaustive list of operations where viewing an automatic schedule outcome for the above efforts helps:
- Original duration estimate adjustments.
- Adding or removing an activity and relationships in the bottom details.
- Adding or removing relationships on the Gantt chart.
- Modifying a relationship type.
- Adding, removing, or adjusting relationship lag.
The advantage of the schedule automatically option for project planning or scope change processes is that it efficiently shows how modifications affect the network logic (Gantt chart), particularly the critical path. In the schedule optimization effort, its advantage is quickly viewing the project end date impact as you execute the listed operations on critical path tasks to compress the schedule.
Ten Six recommends you experiment with scheduling automatically and the above-listed operations in the planning, scope change, and schedule compression efforts. You may find significant productivity.
However, the schedule automatically option is not recommended when progressing the schedule. It should then be turned off. The schedule update process is a three-step process covered in the following article Progressing a Schedule in P6 Professional.
The three-step schedule update process is as follows:
- Enter status
- Move the data date to the end of the reporting period.
- Calculate the schedule.
Let us see what happens when we progress with the schedule, with the schedule automatically option toggled on. We entered the first week’s work status in our demonstration, step 1. The resulting schedule appears as follows in Figure 5:
Figure 5
The problem is that the “Install Piping & Couplings” task, which immediately follows the first week of work, is scheduled at the current data date. This makes the start and finish dates of the remaining work on our Gantt chart too early and does not reflect the actual scheduling situation.
The same updates with the schedule automatically toggled off are as follows:
Figure 6
In the second scenario, the following tasks remain at their current start and finish dates. In this situation, we can conjecture that moving the data date to the end of the first week’s reporting period and calculating the schedule will delay “Install Piping & Couplings” by one workday. We can see that this will push the end date from Friday, the week of June 22, to Monday, the week of June 29.
However, in the previous scenario of Figure 5, we cannot quickly make this assessment because the finish milestone is no longer the project’s current finish date. When the automatic schedule option is toggled, the Gantt chart aligns the remaining work with the current data date and disconnects it from the relevant network logic. This makes continuing step 1, enter status, for the remaining work a confusing proposition.
Summary
The automatic schedule option is useful and schedulers should know this tool is in their toolkit. It is most advantageous for planning, scope change and compression efforts. However, when scheduling updates, the schedule automatically disconnects the Gantt chart tasks from the current start and finish dates to align the remaining network logic with the current data date, which is not helpful.
For further reading on this topic, refer to the blog Primavera P6 Professional and Schedule Automatically Quick Tip.