The Manual Scheduling Mode
just plan it allows to set the global scheduling mode either to "automatic"or to "manual. This is done in the Settings dialog and is shown in the plan by the icons for automatic and for manual mode.
Full control of the plan
In the manual mode, all orders are treated as having the same priority so that plan modifications never directly affect any other jobs despite the selected one. This means that, no matter whether the planner moves a task or changes resource capacities, the tasks of other jobs will never be moved (automatically). The only automatism happening is that the successors/predecessors within the selected job get moved as well.
What will be visualized are the plan’s intrinsic conflicts, such as delayed delivery dates or - in particular - exceeding the defined resource capacities. This means, that in the manual mode, the planner has full control over his plan and has to keep actively solving existing conflicts by drag & drop or by increasing the scarce capacities.
Manual planner's dilemma
Manual mode also means that on the one hand, the planner is always in control of placing his operations with regard to time and their allocation to resources and as a result a planning table with manual mode is completely intuitive. On the other hand, however, solving conflicts manually can also be tricky and time-consuming, this having still more impact when it comes to a constantly increasing number of tasks and resources to be scheduled, if multilevel production orders are to be handled and the plan is dynamic so that modifications have to be carried out on a permanent basis.
The greater the plan gets, the more likely it is that the automatic scheduling mode will gain benefit to the planning process.