How To Fix CY891 - Operation moved because of a fixed time period

CY891 - Overview

• Message type: E = Error

• Message class: CY - Capacity Requirements Planning

• Message number: 891

• Message text: Operation moved because of a fixed time period

System Response

The original dispatching date of the operation is such that the
execution time of the operation clashes with the fixed time period. You
cannot dispatch operations into the fixed time period.
Thus the operations was dispatched to another date.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.

CY891 - Details

• The SAP error message CY891, which states "Operation moved because of a fixed time period," typically occurs in the context of production planning and scheduling within the SAP system. This error indicates that an operation in a production order or a project has been rescheduled due to a fixed time constraint that has been defined in the system.
  
  Cause:
  
  
  Fixed Time Period: The operation has a fixed time period associated with it, which may be defined in the routing or the production order. This fixed time period can be due to various reasons, such as:
  
  Setup times that cannot be changed.
  Dependencies on other operations or resources.
  Constraints related to the availability of materials or resources.
  
  
  
  Scheduling Conflicts: The scheduling engine in SAP may have found that the operation cannot be executed within the originally planned timeframe due to the fixed time constraints, leading to the operation being moved to a later date.
  
  
  Resource Availability: If the