Operating Procedures: Definitions
This post is the fourth in a series to do with Operating and Maintenance Procedures. The first three posts are:
Operating Procedures: Don’t Ask Too Much, and
Operating Procedures: Common Difficulties.
In this post we provide some basic definitions to do with Operating and Maintenance Procedures. In the spirit of the principles of Process Safety Management, these definitions provide guidance only; individual facilities and projects will, and should, develop their own definitions.
Definitions
The definition of operating procedures used in this series of posts is as follows:
Operating procedures are written instructions that, when carried out by the operations personnel, will minimize deviations from design or operating intent.
Operations
Operating procedures should be written for operators, supervisors, and line managers. Other users, such as engineers, auditors, regulators and technical experts may use the procedures, but their requirements are secondary; the operators are the primary customers of the procedures.
Different Goals
Operating procedures are usually expected to serve different goals. There is nothing inherently wrong with this requirement, as long as the nature of those goals is understood and the manual is organized so that they are handled appropriately. The following is a list of some of the varied goals that a manual is often expected to address.
Provide brief, checklist-type instructions to operators and technicians who are fully trained and who are very familiar with the facility and its operation.
Provide detailed instructions for operators who are experienced in general facility operations, but who do not know the particular unit for which the procedures were written.
Provide background and reference information, such as Safety Data Sheets and safe operating limits.
Describe what to do in the event of a major emergency.
Describe what to do in the event of an environmental upset, including the procedure for contacting the appropriate regulatory agencies.
Context
As well as understanding the profile of the person(s) who will be using the procedures, it is also important to understand the physical and social context in which the manual will be used. For example, operators and maintenance technicians often work outside, where they have to contend with high or low temperatures, wind, rain and snow. If they work indoors noise and being plagued with too much information can be issues to contend with. The operating and maintenance manuals should be written and published in a manner such that it is useful to the operator in the place where he or she is actually working.
In many cases the person using a manual will not be sitting at a desk with the book or screen directly in front of him; instead he may be at a control panel trying to following instructions from a manual that is placed on a table that is some distance away, or he may be attempting to read the manual while repairing a piece of machinery while it’s snowing. The formatting of the manual needs to reflect these realities.
A manual is judged not by its appearance, the quality of its written English, the exactitude of the contents, or the sophistication of the software used to deliver those contents — such attributes are merely factors affecting the ultimate usefulness of a manual; instead, an operating manual is judged by whether it is actually helpful to the persons using it. Hence, a shabby, old-fashioned, battered, coffee-stained manual that is frequently used is better than a slick, colorful, user-friendly document that stays on the shelf, or that is lost in a data base somewhere. If the operators choose not to use a manual, then they will not use it; it cannot be forced upon them. Therefore it is the responsibility of those who are writing and publishing the manual to develop a product that is genuinely useful.
Written Instructions
Operating procedures must be written down (either on paper or in an electronic file). Sometimes the operators may have a good set of informal, oral procedures that has never been committed to paper. In these situations, the procedures-writing project consists largely of writing down that informal information in a clear and organized manner.
Design or Operating Intent
Before procedures can be written, management and the operators must clearly define how the facility is to be run; in other words they must determine the design or operating intent for their unit. In particular, target conditions for all flows, pressures and temperatures have to be specified, along with the allowable deviations from those target conditions.
Design and operating intent must be quantified. For example, the following instruction (which is somewhat tongue in cheek) is totally qualitative, and so is not of much value to the operator who is expected to follow it.
Increase the bottoms temperature gradually until the overhead pressure is about normal.
The above instruction can be re-written more precisely as:
Increase the bottoms temperature by 5°C every 10 minutes as measured by TI-213.
When the overhead pressure reaches 3.4 barg, as measured by PIC-221, stop the temperature increase.
Note: The permissible overhead pressure range is 3.0 - 4.0 barg. If the pressure deviates outside this range, refer to Instruction XYZ.
The adverb ‘gradually’ in the first text box has been replaced with numerical values. The word ‘normal’ has been replaced with a number and a safe range.
In the same vein, terms such as ‘crack the valve open’ are unhelpful because they are non-quantitative. Even a phrase such as ‘open the valve two turns’ could lead to an error were the valve trim to be changed. It would be better for the procedures to read,
Open the valve so that the liquid flow, as measured by FR 203, is in the range 90-100 gpm.
Instructions, Not Information
Operating procedures, particularly those written during the design phase, often contain information that does not help the operations personnel carry out their work. Such information can usually be left out. For example, the following statement,
Tank T-100 provides intermediate storage between Units A and B. It should be filled to about 80% level.
is better written.
Fill Tank T-100 to 80% level (±5%) using LI-102.
Maintenance Procedures
The definition of maintenance procedures used here is as follows:
Maintenance procedures are written instructions that, when followed by the maintenance personnel, will ensure that equipment operates as designed within safe operating limits.
The above definition follows the same approach as that used for operating procedures. Equipment and facilities must operate in the safe range. Preventive maintenance helps ensure that equipment stays in that range; repair maintenance restores equipment to its normal function.
Many of the techniques to do with operating procedures can be useful in the preparation of maintenance procedures — however maintenance tasks are not usually so concerned with a long sequence of activities, and they tend to benefit more from the use of equipment sketches and pictures.
Further Guidance
For further information to do with operating procedures, please check out our book Process Risk and Reliability Management.
