Companies with process facilities need up-to-date tools to remain vigilant of Process Safety Management (PSM) and Environmental, Health, and Safety (EHS) risks, especially when it comes to monitoring process and operational changes that could heighten those risks.


One such tool is the Heat and Material Balance (H&MB). Developed early in process engineering for a facility, the H&MB is a foundational document. It typically takes the form of a calculation sheet incorporating operating conditions, compositions, and key physical properties of the major process streams. It can be used to forecast and track volumes and flowrates as well as energy produced and consumed. These numbers guide operational aspects such as production planning, outages, and storage utilization. The H&MB is at the heart of process design and is instrumental to a safe, reliable, and efficient operation.

Since the H&MB looks at the in- and outflows throughout the plant, it provides a check on the overall health of the system. Calculations showing an imbalance may indicate a leak, process upset, or failure in a piece of equipment. If left unresolved, these can result in loss of production or, worse, a Process Safety Event (PSE) or environmental incident, with the potential of long-lasting consequences.


The H&MB and other process-oriented tools are critical for examining changes in the inner workings of the facility, but they do nothing to address another factor that can equally impact production and EHS risk: Organizational Change.

Personnel changes are a reality in every facility. Some changes are permanent. People are promoted; others move on to other functions or even to other employers. Organizations are redesigned with roles and responsibilities being created, eliminated, merged, and redistributed. Other changes are temporary, like vacations, leaves of absence, or short-term coverage gaps. Positions might sit open until a replacement arrives. Sometimes the replacement needs training, turnover information, or simply time to get up to speed. Regardless, vacancies and personnel transitions increase the risk of EHS events.

Poorly managed Organizational Change is a particularly pernicious problem because it can go undetected for long periods and cause serious issues long after the change was made. People and the communication between them are foundational to any operation, and so continuing to operate with poor communication or gaps in responsibilities is like building on an unstable foundation. There may not be any symptoms of a problem at all until the problem is already severe.


Consider the explosion at British Petroleum’s Texas City refinery on March 23, 2005. The blast, which shattered windows in homes and businesses up to three-quarters of a mile away, led to 15 fatalities, 180 injuries, and billions of dollars in victim compensation, property damage, and lost production. It’s considered the worst industrial accident ever experienced in the U.S.

Remedial work had been completed on equipment within the refinery’s Isomerization Unit and start-up of the plant was underway when the ignition occurred. The U.S. Chemical Safety and Hazard Investigation Board (CSB) conducted an extensive review of the incident. Though deficiencies and failures on many levels were identified in their report, the CSB tagged organizational changes as key contributors to the accident.

Under corporate budget cuts in previous years, the refinery had eliminated one of the two control room operators assigned to run the Isomerization Unit plus two others. On the day of the accident, the control room day supervisor left the refinery on short notice and no experienced supervisor was assigned to replace him. This left the one operator without a qualified supervisor to run three units, including one under start-up.

An operator position had been eliminated, but the redistribution of duties and the potential for operator fatigue had not been adequately examined. Decisions made regarding the commencement and continuation of the start-up did not properly account for the additional load placed on the operator by start-up activities or for the effect of the missing supervisor.


While tools such as the H&MB can help avert disasters like that at Texas City, they focus only on the technical side of the equation. What about the administrative side? How can changes in staffing or job functions, along with associated effects on the plant processes, be tracked and managed to avoid unwelcome incidents?

Management of Change (MOC) software can help monitor and facilitate changes of all kinds. This includes changes in equipment, operational procedures, and staffing / organization.

The software establishes and enforces standard procedures for change management and tracks the initiation, approval, progress, and completion of each change. It can identify tasks and workflows, specifying what needs to be done, by whom, and in what order. It can also issue automated notifications to affected personnel. For organizational changes, required tasks might include things like activation/deactivation of security credentials, turnover communications, and the granting or rescinding of access to IT systems. Changes can be identified as permanent or temporary, with specific expiration dates.

MOC software can:

  • Allow easier identification of work tasks.
  • Focus tasks on job positions rather than on specific people.
  • Create temporary roles as may be needed.
  • Foster streamlined turnovers.
  • Help generate what-if scenarios for planning activities like shutdowns.
  • Decrease the likelihood of missed tasks, reports, or opportunities.

To best manage hazards arising from change in process facilities, employ tools that will assist in monitoring and managing not only the technical aspects, but also the administrative and organizational side. Either facet, if mismanaged, can lead to a catastrophic event.