Comparing Models

The Model > Compare command reports what changes have been made in the current model compared to another model in the project; this can be a previously saved version of the same model.

This command opens the Model Comparison dialog. The Model Comparison dialog lists the current model and the model it is to be compared with.

Setting	Description
Current Model	Lists the current model to be compared.
Saved Model	Lists the save model the current model is to be compared to.
List Modifications (Additions, Deletions, Changes)	Enables the report to screen. If the List Modifications box is checked, then a report will be displayed in a standard report writer output dialog (see below) listing the last write date of the files in the saved model and the changed components by category (i.e. Equipment Input: Geometry (script file), Equipment Input: Process (.rpe file), Pipeway Input: General, etc.) The report includes only elements that have been altered.
Highlight Modifications	Enables the highlight options. You may highlight only changed components (Changes), only new components (Additions), or both. Note: If any of the Highlight choices are checked, then all currently highlighted components are unhighlighted, and all new and/or changed components (except steel) are highlighted as selected.
Merge Files (no extension)	Enables the creation of a merge file. See" Merging Models", next.
Apply	Starts the comparison of the two models, and initializes the values for the Infix comparison-result function for reporting.
Cancel	Exits without comparison.

The Comparison Report

A model comparison reports the differences between the process and script files of the current model with those of any saved model in the project (the base model). The report, shown below, notes additions, deletions, and changes for the following PlantWise components:

Equipment
Nozzles
Pipelines
Named inlines
Boundaries
Structure sections
Pipeway sections
Obstacles

Additionally, the summary distinguishes between the following kinds of changes:

Equipment
- process changes
- geometry changes
Nozzles
- process changes
- geometry changes
Pipelines
- process changes
- connectivity changes
- newly frozen
- unfrozen
- changed frozen properties
Inlines
- process changes (for named inlines)
- newly frozen
- unfrozen
- changed frozen properties
Boundaries
- process changes

Users can extract comparison information in a report with the Infix function comparison-result. This function helps you filter reports for changed, new, or unchanged components. For example, to filter a report for changed equipment, you would enter into the Selection Criteria (expression) field:

comparison-result (equipment) is changed

This filter will only report on regular components – such as pipelines or equipment – rather than pieces of components, such as pipeline segments or equipment elements.

After a comparison is run, the values are updated based on the comparison. However, they are not maintained for subsequent changes or model saves — you must rerun the comparison in order to have a valid set of changed data.