Regarding the management of interlocking systems

In terms of management, program unlocking is divided into several levels, with various settings required for each level. Overall, on-site operators are required to monitor the use; if unlocking is necessary due to some issue, there must be relevant procedural approvals, such as maintenance records, which specify the scope of work to be carried out. This process can only be completed and verified with the cooperation of the people using the equipment on site. Any arbitrary changes to the procedure are absolutely not allowed, unless there is the relevant approval and it is signed off by the appropriate personnel. Someone has to be held responsible. It depends on what level you are at – which level of control and supervision applies.

Let me talk about our practices in interlocking management here. 1. A dedicated interlock record book should be established, covering the data that needs to be recorded and the relevant confirmation information related to processes, equipment, and instruments; generally, the daily shift is responsible for completing these recording tasks. 2. Relatively speaking, in the case of any issues related to interlocking, it is usually the process department that puts forward relevant corrective measures, which are then implemented by the equipment or instrumentation teams. It is not separately divided into process interlocks or equipment interlocks. 3. For changes to interlock systems, generally, the process or equipment departments submit their suggestions based on actual operational requirements. The company’s production management department coordinates these suggestions, formulates corresponding modifications to the interlock systems, and after obtaining approval from the design unit, the instrumentation department carries out the necessary actions, with the support of other functional departments. 4. The standards and division of responsibilities will not be discussed in detail here; you can search on Baidu for them. There are many good standards available, so just choose the ones that suit your needs.

This post was last edited by You Yu on 2020-5-15 at 16:59. My personal opinion: 1. Interlock systems should not be divided into equipment interlocks and process interlocks; instead, they must be classified into levels A, B, and C； 2 It is uniformly managed by the instrumentation team (for deactivation, activation, and changes); for any changes, relevant change data and documents must be provided by other teams.

Personal suggestion: (How is your company’s staff structured?) How are the departments established, and what is the equipment allocation for the instrumentation department, especially in terms of DCS systems? Our company’s management procedures are established by the Equipment Management Department (which is responsible for both equipment management and maintenance). Most interlocks are classified into A, B, and C categories, regardless of process or equipment type. The responsibility for maintaining records falls on the instrumentation team within the Equipment Management Department. The activation and deactivation of interlocks are carried out by the on-duty supervisor, as our company has only one DCS maintenance engineer who cannot be on duty 24/7. However, the signing process is quite complex: signatures from instrumentation specialists, safety and environmental protection officers, and process engineers are required to mitigate risks. During night shifts, the general supervisor signs the relevant documents, while those classified as level A require the signature of the general manager. For interlocks, the MOC process is to be followed; major changes require going to the design institute, while adjustments to the interlock values do not require this. The main systems are formulated based on the actual circumstances of your company; they need to be reasonable. No matter how well they are designed, it’s useless if they aren’t put into practice