Industrial companies are undoubtedly interested in running their facilities as safely and productively as possible. Projects of various size scopes at these facilities are driven by these motives as well as others, such as quality and profitability. Care should be taken in the course of project lifecycles to ensure that the project aims are accomplished while also ensuring that process safety is built into the project from its inception, design, construction, and ongoing operation standpoints.
Safe design, construction, and operation of new plant facilities requires thoughtful consideration and collaboration of project teams with internal and external experts to ensure that project work proceeds with the right focus on process safety. One method commonly used to achieve this goal is periodic focused process safety reviews conducted during the project life cycle. There are many opportunities in projects for such reviews, to the extent that it can be confusing what to do, how to do it, and when to do it. It is not a simple one-size-fits all decision. The following discusses some of the available options for process safety reviews to help with these choices.
A systematic process for the selection and implementation of project lifecycle safety reviews is a basic requirement for project management. There are a variety of review types that may be appropriate at different times for most chemical process additions, including:
A hazard identification (HAZID) study is typically the earliest process safety study. The HAZID should be performed in FEL-1 (Options phase of a capital project) and updated in FEL-2 (Concept phase or Feasibility Study phase). It is a brainstorming session based on current knowledge that identifies the potential hazards in the scope of a capital project. For capital projects, the HAZID typically kicks off the initial HSSE Risk Register, which lists the HSSE risks to be managed by the project team. The HSSE Risk Register is usually a subset of the Project Risk Register. Concerns typically addressed at this stage include chemical hazards, siting, traffic, staffing concept, safety concept, flammability concerns, chemical storage, reactivity/compatibility concerns, and waste handling.
A conceptual process hazard analysis (PHA), also called a preliminary or design PHA, is normally conducted during FEL-2. This PHA is typically a HAZOP or What-If study facilitated from early-stage P&IDs or PFDs. However, it can even be facilitated from a process sketch. The depth of information available for the study impacts the specificity of the resulting recommendations. For this and all other project PHAs, engaging an independent, competent, and experienced facilitator is crucial for high quality recommendations to be developed.
As a design progresses, the conceptual PHA should be updated regularly to reflect the increased degree of design and changes to the design, including vendor packages (such as skid-mounted compressors, dryers, heaters, material handling equipment, etc.) when the package information is available.
FEL-2 can also include an early stage Facility Siting study, especially for projects involving new inventories or uses of toxic or flammable chemicals. A siting study is a multi-faceted quantitative analysis of potential fire, explosion, and toxic hazards to personnel from releases of hazardous chemicals. This type of study is extremely helpful in assessing more inherently safe design options, including use of alternate process fluids, minimizing inventories, and location and layout of equipment. The facility siting study should be updated in FEL-3 (Front-End Engineering Design phase) as design decision and inherently safer design options are finalized. It is important for the project to engage well-qualified personnel for a siting study, as facility projects, including those that may impact an existing facility, can involve significant data gathering and complex calculations.
In FEL-3 (Front-End Engineering Design phase), there is typically a series of Design Review Meetings that finalize the process description, controls narrative, and other aspects. The Design Review Meetings are often followed up with the Detailed Design PHA study. The end-point Detailed Design PHA (including a Layer of Protection Analysis (LOPA) study if needed) should be fully reflective of the final detailed design. Any design changes after the Detailed Design PHA need to be managed through the Project Management of Change (MOC) process and may result in MOC PHAs or detailed design PHA updates. Close engagement of process engineers, process control engineers, and process safety/Safety Instrumented Systems (SIS) personnel are critical at this stage.
For larger projects, Construction Hazard Analyses (Construction HAZID, Construction PHA, simultaneous operations review, etc.) often occur during FEL-2 and FEL-3 in a parallel path to the more technical studies above. For projects that are expected to be executed in the vicinity of active processes, these activities are crucial to avoiding undesirable process safety incidents, as many construction contractors are not specifically trained in process safety concerns. At this stage, construction managers and contractor management and HSE personnel should be closely engaged.
Pre-Startup Safety Review (PSSR) and Field Safety Reviews as part of a robust Management of Change (MOC) process are crucial to ensure that construction and equipment is in accordance with design specifications, that operating, emergency and maintenance procedures are ready for use by trained personnel, that all safety recommendations from prior safety reviews are resolved, and similar concerns. For any P&ID changes that are caught at this stage during P&ID walkdowns, an assessment of the impact on the Detailed Design PHA is important at this time.
Many other types of project lifecycle safety review may be appropriate depending on the project scope:
A Codes and Standards review is desirable for larger projects so that relevant industry requirements are identified and agreed early in the project
Formal review of a 3D model by operating and maintenance personnel
A Dust Hazard Analysis (DHA) in accordance with NFPA 652 for potentially combustible dusts
Formal review of pressure relief device sizing
At several project stages, Functional Safety Assessments (FSA) for Safety Instrumented Systems (SIS) in accordance with IEC 61511 / ISA S84
Independent Protection Layer (IPL) validation review to ensure that all IPLs defined in the LOPA for the project meet the requirements of IEC 61511 / ISA S84
Routine construction safety reviews including field walkthroughs, audits, checking for repeat issues, and follow-up on corrective actions
Formal documentation review including verification of readiness of training, procedures, control system instructions, maintenance instructions, safe design limits, functional test results, spare parts readiness, etc.
Companies with highly developed Process Safety Management Systems often have their own methodologies and names for the process safety review activities outlined above, but the concepts and expectations from company to company are generally similar.
Finally, even the best safety reviews conducted during a project are not helpful if the recommendations and actions resulting from the reviews are not appropriately actioned, implemented and tracked to completion. The safety review itself is not the end of the process. A documented method for routinely checking on action status and progress, ideally by someone knowledgeable of the basis for the actions and the consequences of failure to complete them, is strongly recommended.
Failure to implement a strong system of project lifecycle safety reviews and action follow-ups has the potential to cause a higher likelihood of process safety incidents during operation and the corresponding business impacts. Timely project lifecycle safety reviews reduce the impact to project costs due to required safety designs such as inherently safe chemical and equipment options, safety instrumented systems, special piping and materials of construction, and changes to facility siting. Careful consideration and execution of appropriate reviews, including engaging external experts as needed, together with disciplined follow-up on recommendations, will lead to excellent project process safety outcomes.