About Managing Worker Task Changes

This describes Worker Tasks created in a given 3D context, in which the ergonomic assessment that is attached to those tasks is valid. If it changes for any reason (new resource layout, resources at different positions or with different shapes or weights than originally), we need to update.

Some Worker Tasks may need to update, because the risk results that compute in the previous 3D environment may not be valid anymore. Changes on the manufactured product (MBOM) may also have an impact. Finally, changes at the Process Planning level may also invalidate some Worker Tasks, for example if the operation flow modifies.



  1. The sharp icon aspect indicates that the context of this worker task is accurate, thus the risk level is valid.
  2. The icon hatched aspect indicates that the context of this worker task is not accurate, thus the risk level may not be valid.

At the start, the system performs several verifications to warn you that the risk assessment may not be accurate, because action done outside of the app. The hatched icon aspect is the indication that the workers context may not be accurate, thus the risk identification is not valid.

The first verification is on the worker task content. The system verifies that any object referred by the Phrase exists in the PPR structure. If an object is missing, then the Phrase may not be valid anymore. In this case, the corresponding Worker Task is flagged out-of-sync. Moreover, if an object is missing, it frees up some space, thus a previously generated posture may optimize for the surrounding Worker Tasks. Consequently, all the Workers task of the entire system (what operation the worker does) are flagged out-of-sync. This also occurs if any resource used in the Worker Task modifies.

The second verification is at the MBOM level. In this implementation, it cannot identify the modifications cause. If the modification is a shape, it can create/reduce the available space, or change the grasp strategy. If the part’s weight changes, it affects the posturing strategy. Those two types of changes may affect all the Worker tasks where this part is present. Thus, if any of the MBOM parts modifies, the system retrieves the operation that implements (adds) it to the build-up. This also flags out-of-sync all the Worker Tasks of this operation and the following operations, process-wide (not only in the system that the operation belongs to).

There are limitations:

  • This implementation does not support the case where a layout (unused by a worker Task) modifies. Managing such a case requires time costly computation to detect collision and more. This addresses in future implementations.
  • This implementation does not support detecting changes made at the Process and Operation level. In a future release, we may be able to address the following scenario:

    The third verification is at the Process and Operation level. The system verifies if an operation modifies. In such a case, the entire worker process is at risk if the operation order has changed (Flow Link), or if the assignations have changed. If in an operation in a General System, or in a Workplan that has at least one Worker Task, that is modified, all the system’s Worker Tasks flag, as out-of-sync. And it stops scanning Worker Tasks of this system.