Understanding event data collection: Part 2

Editor's note: This is the second of a two-part series. Part 1 appeared in the July 2004 issue.

Most modern process and manufacturing plants use a computerized maintenance management system (CMMS) to help manage maintenance performed on plant assets. CMMS benefits include:

• Baseline of asset information
• Management of store room inventory
• Maintenance work planning and scheduling
• Maintenance history
• Maintenance reporting.

A vital element of these systems is the ability to document history of events that occur within the maintenance work process. Unfortunately, many organizations that use a CMMS either do not use this capability or do not use it to its full capacity. It is important to instill the expectation in the workforce that all work history events will be recorded so that plant personnel can make informed decisions about where and when to use valuable plant resources.

There should be a documented work process in place to guarantee that work history data are collected regularly. The maintenance work management process requires the collection of critical event data at various steps (Fig. 1).

Typically, the first step in the maintenance process is when a work request or notification gets initiated. This usually takes place when an operator, technician, or inspector identifies a problem that requires maintenance attention and initiates a work request to let the maintenance department know that attention is required. Several data elements must be identified and recorded at this point in the maintenance work process. These elements include:

• Location of problem (functional location)
• Equipment ID
• Date the request was initiated
• Malfunction start date
• Failure finding codes (operator routine rounds, inspection, etc.)
• Event type (failure, repair, PM).

Once a valid work request is created and documented, it is reviewed by operations and maintenance for validation. If the request is not deemed valid, it is rejected and then terminated. If it is deemed valid, then a work order is generated. At this point additional data must be recorded on the work order, which includes:

• Location of problem (functional location)
• Equipment ID
• Activity code
• Work order creation date.

Once the order is created and documented, a decision is made to either plan or not plan the work order. After the order passes through planning (if required), it is released to maintenance. Maintenance performs the work and turns the equipment back over to operations upon completion.

With the repair complete and the knowledge of the work in hand, it is time to record that data. Depending on the CMMS, this is either done on the completed work order or the work request. This is by far the most detailed data recording that occurs, because what the problem was and what action was taken to correct the problem are known. The data elements required for this phase of the work process include:

• Location ID
• Equipment ID
• Malfunction start date
• Failure finding codes
• Event type
• Malfunction end date
• Maintainable item
• Damage codes
• Primary cause
• Primary activity.

Once the event has been accurately recorded and all of the cost information has been entered and is deemed business complete, the work order can move to a final closing. When this phase is complete, most of the recommended data required for reliability analysis should be available.

Having a work process to collect event information is only the first step in gathering accurate event history. Without a standardized list of codes to use in your event recording, the data are almost impossible to use for analysis. There are various resources for event recording codes that range from company-specific codes to international industry standards — including the one provided by ISO 14224. This is a standard that was developed for the oil and gas industry and was based on work done by the Offshore Reliability Data group OREDA.

Codes derived from ISO 14224 that are explained in tables within this article include activity, cause, detection method, effect, functional loss, condition, and failure modes.

This standard focuses on equipment as well as failure and maintenance data. It describes details related to equipment classes, types, and boundaries. With respect to event recording, this standard defines codes, time stamps, and remarks. Equipment classes covered by ISO 14224 include:

• Combustion engine
• Compressor
• Control logic unit
• Electric generator
• Electric motor
• Fire and gas detector
• Gas turbine
• Heat exchanger
• Process sensor
• Pump
• Turboexpander
• Valve
• Vessel.

Within these classes of equipment, there are specific codes that can be used to record equipment events. These codes include:

• Method of detection
• Functional loss
• Failure mode
• Maintainable item
• Failure cause
• Maintenance activity.

While these codes and equipment classes are an excellent start, there are additional equipment classes and code categories that are useful in fully documenting an equipment event. Therefore, additional equipment classes are included as supplements to the ISO 14224 standard. They include:

• Agitator
• Boiler
• Fan-Blower
• Fired Heater
• Gas Turbine
• General Equipment
• Meter
• Instrumentation
• Piping
• NPV (Tank)
• Relief Device
• Power Distribution
• Steam Turbine.

Similarly, additional code categories supplement the code categories within ISO 14224:

• Condition
• Effect

A key element of a successful asset performance process is the collection of event data required for analysis. This is especially true if you consider that without event data it is impossible to determine where your problems reside, what strategies are effective or ineffective, and where you need to focus your resources for the largest improvements.

Beyond the ability to measure performance, event data collection gives you the baseline data to perform detailed reliability analysis. These techniques are very powerful when coupled with accurate and complete event data and can drive proactive behavior within the organization. The combination of quality event data, comprehensive analysis, and disciplined follow-through can be the catalysts to meeting your plant's strategic goals.