Proposal of the New Methodology for Process Alarms Optimization At Monsanto Facilities

Abstract: <>

The purpose of this work is to show an overview of the use of a methodology for process alarm optimization at the Monsanto facility, in order to reduce the probability of incidents and accidents on the process. The alarm management is a tool that is included inside the human reliability program established by Monsanto.  The basis of the Human Reliability Program is the Operational Discipline which considers as key factors knowledge, commitment, awareness and infrastructure.

In 2008 was created the first Alarms Guideline for Monsanto facilities in order to Human reliability program. Alarm is a mechanism to helps the operator identify bad process conditions which have to be fixed. Based this Guideline, some Monsanto facilities wrote the internal procedure to alarms management. As improvement this procedure, has been proposed a new methodology for process alarm optimization. The mainly benefits achieved were the development of a methodology for process alarm reduction; reduction of alarm actuation for an average less than established per operator each 10 minutes; an alarm list was created with all plant alarms and troubleshooting to operator action ; alarm prioritization; screen standardization in accordance to EEMUA and ISA. Besides, it was established a systematic follow up of process alarms by data collect using specific software. This tool helps the area responsible for easily have the number of alarms within a period.

This work has as mainly objectives to improve the alarms process established at Monsanto facilities, applying some concepts based in Toyota production system (TPS), six sigma methodology and alarms concepts described in literature , such as, EEMUA (Engineering Equipment and Material Users Association – published 191), ISA (International Society of Automation) e Alarm management Handbook. Two mainly objectives are cited:

a)       Propose the improvement alarms flowchart based on Literature and  knowledge of the process in analysis;

b)       Support the operators to identify and to act in process abnormal situation before the interlock trip to act

Methodology Applied:

The concept found the literature, joined with TPS (Toyota Production System) and six sigma methodologies, allowed proposing the new flowchart for alarms improvement. One step “ergonomic evaluate” was a news added this work due to interaction between alarm system and operator action to correct performance of the system. Therefore the operator condition is very important to guarantee the process control. The step “alarm optimizing” also is important because to allow analysis one alarm before its implementation.

Philosophy Creation:

The philosophy creation has as objective established the basic rules for alarms management, aim to create the concept and standard to implement or change of alarms. This document should contain:  Alarms definition, Risks involved, classification, responsibilities and management of alarms. The goal of alarms per operator per area also should be defined. For this goal the follow standard was defined:

a)       One Alarm should be actuated only the variable is out of range established;

b)       The alarm should not be actuated when its variable return the normal condition;

c)       The alert message and status that not required the action of operator should be configured separated of alarms system.

Data Collect and System Evaluation:

This step should be evaluated the alarms system. The first action is to identify the unit alarms, verify the amount of alarms and describe the alarm list with range limits, band, priority and conditional.  This step should be data collected with the alarms frequency actuated, elaborate the pareto chart to verify the mainly alarms (bad actors). These data will be used in meeting with process team (operators, engineers) to define the actions to solve the alarms problem. The key person for this step is operator due to the extensive knowledge that he has of the process.

Ergonomic Evaluation:

This step was included this work, to avoid some operator attention deviation due to inadequate ergonomic conditions and lost of attention due to noise excess , high environment work temperature, BPCS screen excess information etc.  The following items should be considered: BPCS screen colors, BPCS screen information, adjustable sound alarms, chair adjust, space for notes, telephone ring, presence of the people in control room etc

Alarm Optmization:

This step consist is to review of alarms existing. The following items should be considered: Check if the alarm is important to operation, the amount of alarms (to avoid excess alarms) , if are compliance with system philosophy, limits review, compare to interlock list, compare to critical and operational variable of the process, define criteria of priority, establish conditional alarms, define actions for alarms and create the troubleshooting for operators action.

Training:

During this step the operator has Knowledge of alarms change occurred in the process. This step is very important to refresh some basic alarms concept, such as: What this change intends to avoid in the process?  Why this alarm is important?  Where are applied? and mainly the operator function as key person to good performance for system. After training, the improvement can be realized.

System improvement:

The system improvement will guarantee that the system will be with good performance. Frequently an alarm report should be prepared to evaluate the system performance. This frequency will be defined each unit, can be: diary, weekly or monthly. This discipline is important to maintain the system active and the gaps analysis been done. This work was decided that the frequency will be weekly. This routine is considered very important in some cases during this reports area showed problems instruments that can reach 20% of the alarms amount per operator.

Maintanance:

The maintenance of the system is important to guarantee that the alarms will be checked frequently and tested. Besides, the collected data can be being generated by problems of equipments/instruments. The maintenance support team is fundamental to maintain the process within the optimal process limits.

Management of Change:

This step is considered the control step of the methodology and it has aims to guarantee that all changed occurred will be kept in the future. Therefore, the change needed in the process should consider the alarms system during the changing evaluation. To change, addition, removal of critical alarms, change the conditional, the document must be done ( MOC – Management of Change) and the people involved must be informed and trained.

This work reached two important results: Improvement the alarms management methodology and the alarms optimization in the Monsanto facilities using the methodology developed.

References

Monsanto's Guidelines for Interlocks and Alarms, April 2010

ENGINEERING EQUIPMENT USERS ASSOCIATION - EEMUA. Publicação 191. Alarm Systems. A Guide to Design, Management and Procurement. 1999.

ENGINEERING EQUIPMENT USERS ASSOCIATION - EEMUA. Publicação 201 Process plant control desks utilising human-computer interfaces: a guide to design, operational and human-computer interface issues, 2002.

ISO (International Organization for Standardization) 11064 - Ergonomic design of control centres - Part 1: Principles for the design of control centres, 2000.

NORMA REGULAMENTADORA 17 – ERGONOMIA