The idea here is to create repeatable, high quality methods for operating and maintaining automation systems. These directives cover many of the things that would normally be covered in SOPs – how to manage changes for an automation project, how to submit funding requests, how to track money and time on an automation project. However, these directives also describe an automation system in detail.
Directives related to the field elements of the automation system might describe in detail how main-line pumps are controlled. Directives for the master station would outline how operator interface graphics should look.
Also, many companies that need to monitor and control remote processes spend significant time developing standards for communications between field station and the master station. Often these communication standards include detail memory maps for PLCs – indicating which register should be used to store alarms, set points, calculated points, etc.
Some companies extend this idea to the creation of “canned” automation sub-systems for common applications. For example, one pipeline has a “canned” compressor station automation sub-system. The sub-system consists of a GE 90/70 PLC running a base logic program that can support up to 12 compressors. When deployed, an engineer simply purchases the appropriate GE90/70 model and then customizes the base logic program to accommodate the correct number of compressors at the station to be automated. This “canned” approach can radically reduce the amount of engineering/technician time requires to deploy new compressor automation sub-system.