How To Fix DPR_SHARED207 - Links create a cycle; you cannot schedule

SAP Error Message - Details

• Message type: E = Error

• Message class: DPR_SHARED - Development Projects: Messages for Shared Objects

• Message number: 207

• Message text: Links create a cycle; you cannot schedule

What causes this issue?

The links form a <ZH>loop</>; scheduling is not possible.

System Response

The links between the project elements form a <ZH>loop</>.

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

The system sees both <ZH>relationships</> between the project elements
and <ZH>structural relationships</> (single-level) between the project
elements as <ZH>links</>.
Example:
<ZK>Ph1</>
<ZK> T11</>
<ZK> T111</>
<ZK> T12</>
A relationship has been defined between the task <ZK>T11</> and the task
<ZK>T12</>. The system creates the following links from this
relationship (<ZK>T11, T12</>) [(predecessor, successor)]. The system
then uses the structure relationship to create additional links
dependent on the scheduling type for the tasks <ZK>T11</> and <ZK>T12</>
below the phase <ZK>Ph1</> and for the task <ZK>T111</> below the task
<ZK>T11</>:
Bottom-up: (<ZK>T11, Ph1</>), (<ZK>T12, Ph1</>), (<ZK>T111, T11</>)
Top-down: (<ZK>Ph1, T11</>), (<ZK>Ph1, T12</>), (<ZK>T11, T111</>)
1. Setting up a sort order for processing
The system tries to sort the project elements within scheduling for
processing, based on the links. There are now two cases in which the
message can appear:
a) During sorting, the system finds at least one project element for
which a loop via the links (predecessor, successor, relationship) is
possible.
b) This kind of sorting cannot be set up. At least one project element
that does not have a predecessor via the links is required for this.
2. Creating a relationship
The message can also appear when you create a relationship. This is the
case if the system is to create a relationship for two project elements
P1 and P2 with P1 as the predecessor and P2 as the successor, and a
higher-level project element PP1 of P1 exists and a higher-level project
element PP2 of P2 exists and these are linked by a relationship with PP1
as the successor and PP2 as the predecessor.
Example:
<ZK>Ph1</>
<ZK> T11</>
<ZK> T111</>
<ZK> T12</>
<ZK>Ph2</>
<ZK> T21</>
<ZK> T22</>
A relationship always exists between the phase <ZK>Ph1</> and the phase
<ZK>Ph2</> in the system with <ZK>Ph1</> as the predecessor and <ZK>Ph2
</> as the successor. The system then tries to create a relationship
between the task <ZK>T21</> as predecessor and the task <ZK>T12</> as
the successor.

System Response

The project elements cannot be sorted, therefore, scheduling cannot be
carried out and the relationship cannot be created. The system resets
the data.

How to fix this error?

Remove the loop by deleting the relationships between the project
elements as appropriate.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message DPR_SHARED207 - Links create a cycle; you cannot schedule ?

  The SAP error message DPR_SHARED207 indicates that there is a cyclic dependency in the links between tasks in a project. This means that the scheduling of tasks cannot proceed because one or more tasks are interlinked in such a way that they create a loop. For example, if Task A is dependent on Task B, and Task B is also dependent on Task A, this creates a cycle that prevents the project from being scheduled.
  Cause:
  
  
  Cyclic Dependencies: The most common cause of this error is that tasks are linked in a way that creates a cycle. This can happen if:
  
  Task A is set to start after Task B finishes, and Task B is set to start after Task A finishes.
  There are multiple tasks that are interdependent in a circular manner.
  
  
  
  Incorrect Link Types: Using the wrong type of dependency link (e.g., Finish-to-Start, Start-to-Start) can also lead to cycles if not managed properly.
  
  
  Manual Adjustments: If users manually adjust task dependencies without checking for cycles, this can inadvertently create a loop.
  
  
  Solution:
  
  
  Identify Cycles: Review the task dependencies in your project. Look for any tasks that are linked in a circular manner. You can do this by:
  
  Checking the dependency settings in the project management tool.
  Using the project network diagram to visualize the dependencies.
  
  
  
  Break the Cycle: Once you identify the tasks that are causing the cycle, you need to break the dependency. This can be done by:
  
  Changing the dependency type (e.g., from Finish-to-Start to Start-to-Start).
  Removing or altering the links between the tasks to ensure that there is a clear, non-circular flow.
  
  
  
  Re-evaluate Task Dependencies: After breaking the cycle, re-evaluate the dependencies to ensure that they make sense and that the project can be scheduled correctly.
  
  
  Use Project Management Tools: Utilize project management tools or features within SAP to help visualize and manage dependencies more effectively. This can help prevent cycles from being created in the first place.
  
  
  Related Information:
  
  SAP Documentation: Refer to the official SAP documentation for detailed information on project management and task dependencies.
  Training and Best Practices: Consider training sessions or best practice guidelines for project management within SAP to avoid common pitfalls like cyclic dependencies.
  Support Forums: Engage with SAP support forums or communities where other users may have encountered and resolved similar issues.
  
  By following these steps, you should be able to resolve the DPR_SHARED207 error and successfully schedule your project tasks.