Standard Profits: Make2Pack and ISA88
David Chappell is chair of the Make2Pack/ISA88 Part 5 standards development effort, with Complete Manufacturing Automation Associates - LLC, and retired Proctor & Gamble section manager for batch technologies. Help ISA88 committee members increase dialog about, completion of, interest in, and use of Make2Pack. Join in with your comments or questions to help the standard along, on your way to gaining competitive advantage, reducing overall costs by half. David A. Chappell, Make2Pack chair, and other ISA88 Part 5 committee members provide intelligence and specific links for this effort, spanning OMAC, WBF, and ISA standards efforts.
NOTE: ISA grants permission to post portions of the ISA88 (or other applicable standards) in this blog for comments and discussions and postings (or comments) from this blog may be used for ISA and related standards development.
ISA88 Part 5 draft: Control recipe phase, equipment operation
June 20, 2011
Possible language in ISA88 Part 5 draft standard, Figures 13-15, follow on control recipe phase, equipment operation, and other control concepts. Please provide comments to ensure the standard is understandable, appropriate, and useful across industries and areas of control, machine control, batch control, and continuous control, as well as flexible and scalable, across hybrid applications.
Depending upon their backgrounds and training engineers can have different views of what should be separated into the procedural and basic categories. When evaluating implementations by others sometimes the appropriateness of where a specific part of a functional strategy should exist can lead to a view that control has been blended with both procedural and basic control in and equipment phase, equipment module or control module.
With fewer modules less module to module interaction is required but it becomes more difficult to separate procedural and basic control as represented in Figure 13: Two module implementation with blended control.
The 12 module approach in Figure 14 requires more module interaction but provides possibilities for better isolation and flexibility of control as well are improved reusability.
Engineering determines how much procedural, coordination, and basic control may exist within a single module as indicated in Figure 13 and Figure 14: Twelve module implementation with more separation between control types.
When more than one FS exists within a module generally there is no clear indication of which FS is active as indicated in Figure 15: Module with multiple functional strategies.
Unrestricted access to a module can create performance issues leading to unintended actions by the functional strategy and is often constrained or not allowed.
The type of FS that focuses on equipment procedural control which is recipe aware is found in equipment phases which can be located in a unit or in an equipment module.
Equipment phases have command and control requirements and behave similarly independently of where they reside.
How are the diagrams? Do you understand the draft language? Is it useful across disciplines? Does anything confuse you or require additional explanations? Please comment below. Don't see the comment box? Click here and scroll down.
- David A. Chappell, Complete Manufacturing Automation associates - LLC