Capture process control needs to create functional specifications

Until now, developing accurate, complete, consistent, and generic process control functional specifications relied on spreadsheets, word processors, and copies of previous specifications…with mixed results.

SPEC-Soft’s (Tel-Aviv, Israel) Process Functional Specification (PFS) software uses an object-oriented database to capture, analyze, and document process control requirements in a manner that encourages an iterative development process.

Designed to run on Microsoft Windows 98/NT platforms, PFS provides forms-based-entry to collect physical and procedural process control information and store it in a relational database.

Start with what you have

When Piping and Instrumentation Diagrams (P&IDs) are developed in a .DWG file format and drawing objects for such things as pumps, valves, vessels, and heat exchangers, are used, the drawings can be imported and used to automatically populate PFS’s database of physical objects.

PFS views a plant as a collection of process cells, each containing three classes of objects (control modules, equipment modules, and units) consistent with ANSI/ISA S88.01 standards.

Graphical and text tools are used to develop logical and computation algorithms to define process control calculations and interlocks.

Process cell procedural requirements are developed using SFC (sequential function chart) and text tools. Each procedure is assigned to one of three classes (procedures, operations, and phases) consistent with ANSI/ISA dS88.02 draft standards.

Process flow paths of physical and procedural entities are connected together using a connector tool. When all connections are completed, analysis wizards examine routes and identify path and usage conflicts, an especially beneficial feature in identifying process flexibility bottlenecks.

Using the Microsoft Windows Explorer tree style, classes of physical and procedural entities are displayed in a parent/child hierarchy that permits expanding and collapsing of viewed information.

Hard-copy functional specifications are developed using free-format text developed in Microsoft Word with the ability to insert tables and diagrams retrieved directly from the database.

Birth-to-grave usefulness

Frequently functional specifications end up on a shelf shortly after the project is awarded, and process control requirements are reestablished in a new format on a different platform.

PFS’s flexibility and focus on capturing process control requirements permits it to remain an integral part of a processes life cycle, even if the control system changes. For example, control strategy changes, test plans, testing results, and other change-management issues can become a part of PFS’s database.

A future release of PFS would benefit from a more comprehensive recipe-definition method, but the current version captures and documents process control requirements more efficiently than traditional methods.

For more information, visit www.controleng.com/freeinfo Comments? E-mail dharrold@cahners.com

Author Information

Dave Harrold, senior editor dharrold@cahners.com

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