Ortems HowTo SolutionUpdate Business
The functionality ‘Dependency links between WOs” has been introduced with DELMIA Ortems 2021 Golden (Fix 2038)
When using total precedence link, this implicates a total precedence between 2 operations. The introduction of the “Dependency links between WOs” functionality allows now to have a total precedence between 2 WOs.
This new type of link can only be created, edited and deleted from the WIP Control application. After being created, these direct dependencies between WOs are visible in the Planning application, and constitute planning constraints like any other types of links.
The link always starts from the end of the last operation of the 1st WO to the beginning of the 1st operation of 2nd WO.
This new link appears in purple color in the plan.
How to set “Dependency links between WOs” ?
Through the WIP Control application, WO management > WO.
At this step, by opening a WO and going on the “WO dependency” tab on the bottom right panel, it allows to create the links.
It is then possible to choose using the “Display” drop list to see the links only related to the selected WO or to see all the WO links.
Some cases showing how the link behaves in the planning
Once the link has been created, the link appears as followed in the planning.
From a WO Gantt chart or WO focus Gantt chart, clicking in the left panel on a WO ID pops up the WO description with a new “Dependencies” tab showing the dependency links:
Why the positioning of the link change ?
The source and destination operations of a dependency link can vary over time, according to the changes brought to the plan, or to the progress of the WOs.
For instance, when fixing the starting date of the green 0020 operation to a later date.
The link is now established between the blue 0040 operation and the 0010 green one.
This is explained by the fact that the link is between 2 WOs and not between specific operations.
In the case of an operation deletion :
Starting back from the initial situation, what happens if the upstream or downstream operation of the link is deleted ?
In the below example, after blue 0040 operation has been deleted from the planning, then the planning creates a link between 0030 blue operation and 0020 green operation.
The multiple link display management
If a downstream WO has several start operations with one or several end operations from the upstream WO, for clarity sake, the application displays a single dependency link between the 2 WOs. The Dependency link is then displayed between the operation with the latest end date for the upstream WO and the operation with the earliest start date for the downstream WO.
To illustrate that point, in the below example, 0040 blue operation has total precedence link with 0010, 0020 and 0030 green operations: the dependency link is set between 0040 blue and 0030 green:
However, in case where all the operations of the downstream WO have the same start date, Gantt charts display then the link for each of them.
If now, the start date of the 0040 green operation changes by being fixed earlier, the dependency changes accordingly.
Namely, only the most constraining link between WOs is visible.
Some more words about the feature
In the Planning application, dependency links between WOs:
- Are planning constraints that apply when scheduling and sequencing the plan.
- Are visible like any other type of link between WOs (that is, using highlighting features, or the button in “WO” tab of the control ribbon) but have a specific color.
- Generally speaking, behave as other total precedence link
Technical consideration
This new feature is stored and settable in B_WO_DEPENDENCY table.
B_WO_DEPENDENCY is the static data table used at the WOs launch as E_WO_DEPENDENCY is the dynamic table (fed from the WO launching) used by the Planning program.
