May I ask everyone, how are critical equipment classified in a company?

The use and maintenance of critical equipment play a very important role in a company’s production equipment. If these devices fail, it can lead to shutdowns, halting of production lines or production systems, and resulting in significant economic losses. For example, boilers and air compressors in utility systems can cause the entire plant to come to a stop if they fail, and improper handling of such situations may lead to accidents; therefore, it is necessary to make accurate assessments during risk identification and take appropriate measures.

We use the \"eight-factor method\" to classify equipment into three categories: A, B, and C, with category A representing critical equipment. For important equipment in utility systems such as air compressors, backup units are usually available; therefore, they are not necessarily classified as critical equipment – it depends on the decision made by the company’s equipment department. Analysis method for critical equipment—The eight-factor method classifies equipment as critical based on the value of its criticality index, namely the Cr value. 1. Calculation formula: Cr = K * C
Cr: Equipment criticality index
K: Potential impact factor
C: Failure probability (based on historical data)

2. Algorithm for the failure factor C:
10 = Failures occur once every 2 weeks to 1 month or more frequently
8 = Failures occur once every 1 to 3 months
7 = Failures occur once every 3 to 6 months
6 = Failures occur once every 6 months to 1 year
5 = Failures occur once every 1 to 3 years
3 = Failures occur once every 3 to 5 years
1 = Failures occur once every 5 years or less frequently

3. Algorithm for the potential impact factor K:
K = D + (E + 6*F + G)/3 + (H + I + 6*J)/3
D: Potential hazard factor (potential EHS impact)
1 = No safety risks
3 = Possible safety risks
5 = Clear safety risks
E: Production time loss factor
1 = No loss of production time
3 = Loss of 1–24 hours of production time
5 = Loss of more than 24 hours of production time
F: Product value loss factor per unit of lost production time
1 = Auxiliary process system; no impact on process parameters or product quality
3 = Auxiliary process system; impact on process parameters and product quality
5 = Main process system/main utility system; risk of shutdown
G: Product inventory status factor
1 = Sufficient inventory; no impact on downstream processes
3 = Moderate inventory level; some impact on downstream processes
5 = No inventory; severe impact on downstream processes
H: Maintenance resource requirement factor
1 = Can be handled internally or by maintenance contractors
3 = Requires outsourcing to qualified construction units
5 = Requires outsourcing to qualified construction units along with technical expertise
I: Reliability factor of backup equipment
1 = Online backups (multiple units available)
3 = Backup inventory or supplier stock available (1 unit available)
5 = Long lead times or long repair times (no backup equipment)
J: Maintenance cost factor
1 = < 20,000
3 = 20,000–100,000
5 = > 100,000

What are the A\B\C classification criteria? Thank you

Class A equipment: Critical equipment. Equipment that meets the following conditions is classified as Class A equipment: ① Equipment with a high criticality index according to the eight-factor method is considered Class A critical equipment； ②It plays an important role in the production process; it refers to sets of equipment or units that are responsible for the production of a particular device or product, and have a direct impact on product quality, output, and the manufacturing processes. Accidents or failures of such equipment can directly lead to interruptions in the production process of devices or unit products, a decline in quality, significant impacts on safety and the environment, and even affect the entire production structure of the company. ③Single devices that pose a direct threat to personal safety and environmental pollution, or those with heavy production tasks; or devices that suffer from frequent failures, have a low utilization rate, and are difficult to upgrade or modify technically. ④Large, precision equipment with high value, complex maintenance requirements, difficulties in acquiring or manufacturing spare parts, and particularly high maintenance costs. ⑤Instrumentation and equipment related to important control loops, etc. Class B equipment: Critical equipment. Equipment that meets the following conditions is classified as Class B equipment: ① Equipment with a high criticality index according to the eight-factor method is considered Class B critical equipment ； ②Devices with high specificity (such as high flow rates, high pressures, high temperatures, etc.), few opportunities for online replacement (1 backup unit), high precision requirements; devices that can cause certain impacts on the production process of apparatuses or unit products in the event of accidents or failures, or that may lead to shutdown risks for other critical and important equipment. ③Equipment that poses an indirect threat to personal safety and environmental pollution. ④Large and medium-sized, precision equipment that is of high value, difficult to manufacture, and requires high maintenance costs. ⑤General interlock circuit instrumentation, general control circuit instrumentation, critical measurement circuit instrumentation, critical analytical instruments, alarms, etc. Class C equipment: General equipment. ① Production equipment that is not critical or important equipment is referred to as general equipment. When accidents or failures occur in such equipment, their impact on production is minimal; they do not cause reductions or stops in operations of the main production lines. Moreover, they pose little or no threat to human safety or environmental pollution. There are usually alternative devices available (one or more). ②Equipment that is simply designed and manufactured, has an outdated structure, or is in \"overdue service\" and lacks value for repair. ③Equipment with few or no technical difficulties in maintenance, low or minimal maintenance costs, and spare parts that are highly interchangeable, simple to manufacture, or of average value. ④Other instrument equipment besides Class A and Class B

The specific circumstances of each company cannot be exactly the same; this is for reference only.

The specific circumstances of each company cannot be exactly the same; this is for reference only.

Key equipment: importance within the device and system, cost of the equipment itself, rarity of replacing the equipment, difficulty in securing its main components

The teacher upstairs shared very professional insights; I learned a lot from it, as they provided us with an overall approach and methods for classifying equipment. I think the specific requirements vary slightly from one facility to another. For example, in sewage treatment plants, online monitors for various parameters, online monitors for ozone used in disinfection, and online detectors for residual chlorine are all quite important, as they directly determine whether the treated water meets the required standards. But in other companies, these devices do not affect production.

The ABC classification method can be found online