Using Cycle Constraints in the Resource Gantt Chart

	Cycle constraints are used to show the priority relation between defined cycle times amongst processes of the individual cycle times in the Resource Gantt Chart. The standard cycle time is set to 25 seconds. Defined cycle constraints relations can be saved on a long-term basis only if the project is created in the Process Engineer (PE) and then is loaded in accordance with V5 and then saved again after the definition of the cycle constraints. Saving the cycle constraints is absolutely necessary in order for the defined cycle constraints relations to be accessible on a long-term basis as well as after the repeated loading of the project from the Process Engineer. If you do not save at this point, the defined cycle constraints relations are lost. The structures and relations between resources and processes should generally be available in the project. If the Process Engineer is configured accordingly, the defined cycle constraints relations can be displayed for processes after the project is saved under the attribute must precede process in previous cycle. In order to create a cycle constraints relation between processes you can use the following views for selecting processes in V5: PPR tree Pert Chart Product Flow Viewer Gantt Chart Resource Gantt Chart The defined cycle constraints relations are displayed with arrows in the Resource Gantt Chart: A blue arrow indicates that there is a cycle constraints relation between processes. A red arrow indicates a violation of the cycle constraints relation. A green arrow indicates the cycle constraints relations whenever the end and start date of both processes (between which a cycle constraints relation exists) are set for the same point in time. The cycle time can be edited in the Resource Gantt Chart.
	Creating constraints relations
	In order to display cycle constraints relations in the `Resource Gantt Chart`, activate under `Tools> Options> Gantt Chart` the option`> Display cycle time bars.` You can use the Cycle constraints to define the priority relation of the processes between the cycle times. You thus set which process in the first cycle must be terminated before a process to which the priority relation Previous Cycle Constraints exists can begin in the second cycle. The example shows how to define the cycle constraints for two processes: The process Operation3 has the priority relation Previous Cycle Constraint to Operation1, i.e.: Operation1 can start in the second cycle only if Operation3 was terminated in the first cycle. In order to create a cycle constraints relation, select a process - Operation1 in the example. Click `Constraints between Cycles` in the Activity Management toolbar. Select the second process; the selected process is shown in the dialog Constraints to Previous Cycle - Operation3 in the example. Click `OK` to close the dialog and confirm the entry. The cycle constraints relation is created between the two processes. A Previous Cycle Constraints Relation can be removed; select the process in the list of the dialog, then click on the button Remove. Save the settings after closing the dialog.
	Displaying and editing cycle constraints in the Resource Gantt Chart
	Open the Resource Gantt Chart after you have defined the cycle constraints relation. To do this, click `Open Resource Gantt` in the Data view toolbar. Additional information on the Resource Gantt Chart can be found in the chapter Monitoring Resources with the Resource Gantt Chart. The following examples will familiarize you with the procedure: In the examples six processes (Operation1 to Operation6) are linked to two resources (Resource1 and Resource2). Operations one to three are linked to Resource1, and Operations four to six are linked to Resource2. In the example, Resource2 is first selected and then Resource1 for the display of the resources in the Resource Gantt Chart. Furthermore, the following cycle constraints relations are defined between processes: Operation3 has the previous cycle constraints relation to Operation1 Operation4 has the previous cycle constraints relation to Operation3 The defined priority relations are marked by the blue arrows in the Resource Gantt Chart. Conclusion The result of these defined priority relations shown in the Resource Gantt Chart is that the process Operation3 must be terminated in the first cycle before the process Operation1 can start in the next cycle. Furthermore, process Operation3 can start in the second cycle if process Operation4 has been terminated in the first cycle. The blue arrow indicates the cycle constraints relation between Operation1 (second cycle) and Operation3 (first cycle). The green line indicates the end of the first cycle and the start of the second cycle. The standard cycle time is set to 25 seconds. The green arrow also indicates the cycle constraints relation between Operation3 (second cycle) and Operation 4 (first cycle) - in this case the start date of Operation3 and the end date of Operation4 are set to the same date. In the example the cycle time was changed from 25 to 20 seconds, which led to all of the start dates of the process in the second cycle to be changed. By changing the cycle time the cycle constraints relation between Operation3 (second cycle) and Operation4 (first cycle) is violated. The red arrow indicates the violation of the cycle constraints relation between Operation3 and Operation4.
	Limitation Cycle constraints relations between processes are not supported by the Resource Gantt Chart. A violation of the cycle constraints relation may occur, for example, whenever the cycle time or process time is changed.