The sample workspace shown in Figure 8.2 organizes schema documents for control stations regulating several processes in multiple plants of the same facility. The workspace maintains all the schemas for mulitple systems in the facillity. It uses folders to organize the schemas into meaningful groups--much like an operating system uses folders to group related files. For instance, the sample workspace of Figure 8.2 contains top-level folders, one for each main machinery room (MMR) in the plant (named MMR1, MMR2, etc.). Each top-level folder contains three sub-folders named Boiler A, Boiler B, and Feed Pumps. The Feed Pumps sub-folder contains the three hardware interface files and associated schemas for the three control stations that regulate the feed pumps in the machinery space. The Boiler A and Boiler B sub-folders contain the hardware interface files and associated schemas for the control stations housed in the main machinery room.

Figure 8.2. A sample workspace.

Clearly, the grouping of schemas within a workspace is arbitrary. In the sample workspace, we could have chosen to eliminate all sub-folders, and maintained only the top-level folders corresponding to each main machinery room. For that matter, we could have eliminated using folders altogether and maintained all the hardware interface files and associated schemas at the workspace root. Another approach would be to maintain four separate workspace documents---one for each machinery space. Or we could have combined the sample workspace with workspaces for other plant, or with workspaces for controls systems on all plants of a particular type.

The benefit of maintaining several systems within the same workspace is that you can easily access all the hardware interface files, human-machine interface files, and schema documents in the workspace. To open a document, you simply double-click on the corresponding item in the workspace window. You don't need to search your drive directories for the desired file---the workspace knows where each file is located. The drawback of maintaining a workspace with many schemas is that it may become needlessly complex.

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