Overview

Documentation comes in many forms, from general layout drawings to detailed schematics. It also includes parts lists, the theory of operation, specifications, purchase order data, preventive maintenance procedures, software configurations, training manuals, and any other helpful documentation. Process (piping) and instrumentation diagrams (P&ID), loop diagrams, and the equipment manufacturers' documentation will be the documents most used by the maintenance department. Some companies call the P&IDs "piping and instrumentation diagrams"; others call them "process and instrumentation" or other names, but the format is the same.

Good documentation means up-to-date information and as-built drawings. Improper revisions of the documentation can cause a bigger problem than a limited amount of good documentation. It is in maintenance's own interest to see that if any changes are made to the process or its controls, the respective P&ID and loop diagrams are revised immediately. Poor documentation can also be a safety hazard or a product loss. Maintenance is generally done during operation on most continuous processes and sometimes in the middle of a batch process. If improper documentation causes the wrong loop to be upset and the process goes into a critical stage, the product run could be lost or a hazardous malfunction could occur.

New to the maintenance department is the requirement to understand some software documentation. Some of this documentation is listed in a database and is not listed in manuals or on hard copy.

Diagnostics help maintenance personnel in locating the problem. In some cases diagnostics tells what card to change or...