Optimistic and pessimistic operations - SmartPlant Foundation - IM Update 46 - Help - Hexagon

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SmartPlant Foundation / SDx Version
10
SmartPlant Markup Plus Version
10.0 (2019)
Smart Review Version
2020 (15.0)

Concurrent engineering or long term transactions can be performed in a pessimistic or optimistic mode. These modes can be set across the entire system or set against a specific project.

Pessimistic mode - Only one project can make a change to as-built data at any one time, because this is the only way that you can guarantee data integrity. Data items and documents are claimed exclusively into one project before modification and cannot be altered by another project or at the plant level.

Optimistic mode - Many projects can work with the same data. The term optimistic refers to the success or not, of consistently merging data back to the as-built level without loss of data from previous project changes. Items are no longer exclusively claimed into one project at a time.

Other users can still edit the original records, as the user's changes are isolated, and also make changes at the higher configuration plant level.

There are many examples of when it is necessary to work in the optimistic mode. For example:

  • General Arrangement diagrams that are shared between multiple projects, where more than one project may change this reference data.

  • Large equipment, such as towers, which may well have more than one project modifying it at a given time.

  • Lines, which are also frequently modified by more than one project at a time.

  • Junction boxes, in which multiple projects may be modifying connections.

Features in both modes

  • Plant items under change in a project are clearly marked as under change, and this information is available as a column in the list view. Additional information is available in the form of item details or item reports, such as a list of all lower configurations to which it has been claimed.

  • A report is available to see which plant items are under change and in which project to review future changes to the plant item.

  • A similar report shows the differences between the current plant version and the future project version.

Additionally, the following features are provided for managing the optimistic mode of operation, although to insure rigorous data integrity, they are also available in the pessimistic mode of operation.

  • On merge, the system determines if the design basis of the project has been superseded, for example, by a merge of another overlapping project. If the answer is yes, then you are presented with an interface to help you address the data mismatches created by the other merge operation.

  • When a change is made that causes a project design basis to be superseded, the users working in that project are notified.

  • Any items that are superseded in this way are clearly identified to the users and reports show the differences between the item versions in the project and plant. This report can be run to identify differences between single selected items or at the project level to identify all superseded items.

  • When an item is superseded in this way, it is possible for you to resolve the conflicts without actually merging it. This means that the project item is now considered to be consistent with the current plant version and so does not show up in the reports as a conflict.