Additional Windchill Capabilities > Manufacturing Process Management > Windchill MPMLink Overview > Key Manufacturing Concepts and Terminology > Cache Mechanism in BOM Transformer
  
Cache Mechanism in BOM Transformer
The use of cache mechanism is effective when a large number of parts are present in the tree structure in BOM Transformer or Service Associative Part Structure Browser (SAPSB). The advantage of using cache mechanism is that after the initial loading of the structure in cache, the subsequent actions are executed relatively faster. You can use this mechanism to boost the performance of BOM Transformer.
Working of Cache Mechanism
The prerequisite to leveraging the cache mechanism is setting the user preference Enable Structure Cache to Yes. With this configuration, the entire structure information of a session is stored in cache. After the preference is configured, the process of building a cache starts in the background when you open a BOM Transformer session. A separate cache is built for every BOM Transformer session. The time taken to build a cache depends on the size of the structure.
The cache is updated when changes are made to a subassembly, an assembly, or a part. The cache is incrementally updated only for that subassembly and not for the entire structure. The cache is rebuilt if the root node is changed.
The upstream and downstream tree structure of BOM Transformer have separate caches and both are updated independently. When you modify a structure in downstream, only the downstream cache is updated. While the downstream cache is being updated, you can modify the upstream structure. However, PTC recommends that you invoke a user action on the structure only after the cache building process is complete. During the cache building process in downstream, if you invoke an action in upstream that has an impact on the downstream structure, the action will be executed only after the cache building process in the downstream is completed. For example, Select Equivalent Parts on Other Side.
The status on the cache building process is displayed below the BOM Transformer toolbar. The following table provides information about the status messages of the cache building process:
Message
Description
Cache Building Status: Uninitialized
The cache is not built for the given structure.
Cache Building Status: Complete
The cache building process is complete. The subsequent actions will now use cache for their execution.
Cache Building Status: In Progress
The cache building process is in progress.
Cache Building Status: Failed
The process of building cache has failed. You can rebuild the cache. Click Build Structure Cache in the middle pane toolbar of BOM Transformer or SAPSB to rebuild the upstream and downstream cache.
* 
is visible only if the Enable Structure Cache preference is set to Yes.
The process of building cache may fail due to the presence of recursive paths in the structure. Recursive path occurs when a child part references its parent part. Rectify the structure before you rebuild the cache.
The following actions use cache:
Select Equivalent Parts on Other Side
Select Equivalent Occurrences on Other Side
Select Equivalent Usages on Other Side
My Checkouts
Quick Search
View Equivalent occurrence status
Update Equivalent occurrence status
The following actions result in updating the structure information and rebuilding the cache:
Insert Existing
Insert New
Insert Multiple New
New Downstream View
New Downstream Part
Paste as a New Branch
Paste as a New Part etc