I have a list that contains a large amount of technical data that includes drawings and engineering documents. Is it possible for each item (an individual drawing or document item) to have sub items (Temporary Revisions or Engineering Change Orders) associated with it in the original list? I know I could attach the minor change docs with the original document in the main list item but I am wanting to keep them separate to track individual revisions and changes to each of the minor changes until they are incorporated into a major revision of the original document. Any help would be greatly appreciated.
Are you using a list or a library? If you want to track revisions and changes to files, a library would be more suitable than list items with attachments.
You may want to have a look at Document Sets. Document sets in document libraries allow the grouping of documents that have something in common. The document set can be defined with certain metadata, the documents inside the document set can inherit metadata from the document set. It's easy to add items to a document set and it has a few other useful features, like version snapshots.