Show TOC

 Relationship

Definition

The linking of the start and finish points between two operations in an order, an order network, a network or a standard network.

In an order, a relationship describes the processing and temporal dependencies between two operations. For example, it can specify that a particular operation can only start once another operation has been completed, or that an operation cannot be completed before another operation has been completed. The operation becomes the predecessor or the successor to another operation through the relationship.

Use

A relationship defines how two operations should be sequenced in terms of time.

In order to plan and execute extensive maintenance work efficiently, the sequence and dependencies between the individual operations are very important. It is therefore important to relate the operations for an order to one another in terms of time, in other words, to network them. You can do this using the networking functions and relationships.

You can network both the operations within a particular order and the operations from different orders with one another.

Note Note

If you create an order without networking the operations explicitly using a particular relationship, the system automatically schedules the operations as for a start-finish relationship with a time interval of zero.

End of the note.

Structure

Relationships are characterized by the following:

  • Type

  • Time interval between the operations

Relationship Types

The following relationship types are available:

Finish-Start Relationship

The end of one operation is linked to the start of the subsequent operation.

The operation "Install equipment" can only start once the operation "Repair equipment" has been completed.

The finish-start relationship with a time interval of zero is the standard case in Plant Maintenance.

Start-Start Relationship

The start of an operation is linked to the start of the subsequent operation.

The operation "Painting" can only start once the operation "Put up scaffolding" has started.

Finish-Finish Relationship

The end of an operation is linked to the end of the subsequent operation.

The operation "Take down scaffolding" can only be completed once the operation "Painting" has been completed.

Start-Finish Relationship

The start of one operation is linked to the end of the subsequent operation.

The operation "Put in process" can only be completed once the operation "Acceptance" has begun.

Overview of Relationship Types

Time Interval Between Relationships

The time interval is the time between two operations which are linked by a relationship.

Example Example

Operation 0020 is linked to operation 0010 by a finish-start relationship with a time interval of two days. This means that operation 0020 can only start two days after operation 0010 finishes.

End of the example.

You can enter the following types of time interval between linked operations:

  • As positive or negative absolute values

You enter an absolute value, for example, 10 days. In the case of a finish-start relationship, this means that operation 0020 starts 10 days before the completion of operation 0010.

  • As a percentage of the duration of the preceding or subsequent operation

You enter a percentage value, for example, 80 %. In the case of a start-finish relationship, where the preceding operation 0010 has a duration of 10 days, the subsequent operation 0020 starts 8 days (= 80% of 10 days) after operation 0010 has finished.