Ahmed Sobhi
A good question. In this issue, we will discuss a quantifiable measurement method, linking the effectiveness of surveys to operation and maintenance costs. The effectiveness of surveys greatly depends on what is being measured, how well it is documented and whether there is follow-up on specific actions and recommendations. Here is a brief overview of the types and frequency of surveys.
Installation surveys could be helpful for a plant. Typically, an 80/20 rule applies, e.g. 20 percent of pump bad actors cause 80 percent of problems. More specifically, from a pump population at a given plant, 80 percent usually work fine, and 15 percent work somewhat less well, but operators and maintenance personnel have learned to live with the problems. The remaining 5 percent cause the most headaches. The problem is that these pumps are not always well documented, due to labor turnover, lack of systematic follow-ups and updates, lost records, etc.
An annual survey is a good way to tie up loose ends and update records of a plant pump population. It is similar to the annual parts inventory count, which purchasing and inventory control people perform at manufacturing plants. It is typically a one week program (depending on plant size; large plants could take longer) to survey the machinery, fill out forms, document operating conditions and the criticality of each installation, list the number of failures or stoppages, and produce a survey report.
Some plants (usually larger ones) conduct more comprehensive surveys, with a goal of identifying, documenting and gathering data for loading in a Computerized Maintenance Management system (CMMS). This type of survey is extremely involved since a database has to be created for all of the plant's pumps. At one site with 1,200 pumps, a six person team surveyed all the pumps in one year. Most of the pumps had no tags, and the vendors had to be contacted to identify types. The pumps had to be disassembled to measure impeller diameters, etc. There are companies with existing databases that do this type of gathering and data management, and it is significantly more costly.
An annual survey should be followed by a monthly survey and weekly and daily records. If an annual survey is done thoroughly and properly, the monthly surveys should not be too lengthy, perhaps taking one day. The weekly records could be a one hour exercise to note any abnormalities. The daily log is part of the ongoing operating procedure that operators and maintenance departments go through routinely.
A plant can have the surveys performed by their own personnel, such as a reliability team, or subcontract the services of a consulting agency. Each approach has benefits. An internal team, if established and active, may be more intimately familiar with plant issues and have quick access to other departments, if needed. However, it may not have sufficient time and resources to stay focused on the program, due to manpower limitations, emergencies, interruptions and turnovers.
A consulting agency can take time to familiarize itself with the plant specifics, but can maintain consistency, plan follow-ups and provide an independent and unbiased evaluation of the plant equipment operation and alternatives.
Whether you work at a large corporation or a small privately held company, we would like to hear about the experiences, successes and issues you might have encountered when dealing with this subject.