What is ProjectWise doing?

Maybe you have read an earlier blog of mine discussing bandwidth and latency (ProjectWise Killer). Even in a best-case scenario, you may still find yourself asking why it takes a few seconds longer to open my drawing from ProjectWise compared to your Windows shared drive.

That is because documents are not merely ‘opened' in ProjectWise. Rather, documents are now ‘Checked out', which is probably the most commonly used user function within ProjectWise. As you know, users can check out a document in a variety of ways. Regardless of how they choose to do this, the ProjectWise datasource process remains the same and it is transparent to the users. However, it helps to understand how this operation performs behind the scenes:

1. The ProjectWise Explorer sends a message to the ProjectWise Server, asking to check out the specified document.
2. The ProjectWise Server retrieves all pertinent database records in order to decide if the user should be allowed to check out the document. At a minimum, this would include the current status of the document (is it already checked out to someone else?), and the access control list for the document.
3. Assuming the user is allowed access to the document, the ProjectWise Server executes a database transaction, changing the document status to Going Out.
4. The ProjectWise Server then determines the Storage Area for the specified document. This information is sent back to the client. The client then initiates a conversation with the system hosting the Storage Area, indicating the file to send.
5. The file is then transferred from the Storage Area to the user's Working Directory, and placed in a sub-folder of the same name as that of the folder on the server (dmsXXXXX).
6. When file transfer is completed, the file is verified for completeness and the conversation with the Storage Area system is terminated.
7. The ProjectWise Explorer then sends a message to the ProjectWise Server indicating a successful check out.
8. The ProjectWise Server completes the operation by executing a database transaction, changing the document status from Going Out to Checked Out.
9. Finally, the ProjectWise Server executes one last database transaction. This transaction writes a record of the document, user, system, time, and date of the check out.

The check in process is the reverse of the check out. The only significant difference is that when the document is being checked in, the temporary status is set to Coming In. By the way, Going Out and Coming In are legitimate database values for document status, but only temporarily. If a document appears to be permanently in either status (you will see this in the Status setting on your Document > Properties page), it indicates a transfer problem. If this occurs, contact your PW administrator to decide on the best course of action.    JP