View & Thoughts

Safety Case – a journey worth every effort

Participants of the joint study mission to Europe (government agencies, union, industry)|Safety Case Written Presentation documents|OSV discussion between MHD officers and PCS’ Safety Case Development Organisation|OSV discussion between MHD officers and PCS’ Safety Case Development Organisation|All smiles at the end of the Conclusion Meeting|||

By Bernard Leong, 
HSE, Petrochemical Corporation of Singapore (Private) Limited (PCS)

What is Safety Case ?

A Safety Case written presentation is commonly presented using (and communicated through) a structured set of documentation that focuses on how major accidents are prevented at Major Hazard Installations (MHI), and how the consequences to people and the vicinity are limited.

MHIs comprise petroleum refining facilities, petrochemical manufacturing facilities, chemical processing plants and installations where large quantities of toxic and flammable substances are stored or used.

MHIs are covered by the Workplace Safety and Health (Major Hazard Installations) Regulations which came into operation from 1 September 2017. In it, the occupier (company) of a MHI must take all measures necessary to reduce the risk of major accidents to as low as reasonably practicable (ALARP) and to limit the consequences of major accidents.


The core feature of the Regulations is the Safety Case Regime. This regime allows flexibility for MHIs to tailor their risk mitigating measures, enabling MHIs to address their risk in a more holistic manner.

The development of the Regime was with close collaboration of regulatory authorities, led by Ministry of Manpower (MOM), and the industry, led by Singapore Chemical Industry Council (SCIC).

As early as 2013, HSE Manager, Er. Bernard Leong LW, participated in the MHI Study Mission, led by MOM. The tripartite (government agencies, union, industry) study mission to Europe was to understand the framework on the management of MHIs in the context of Seveso II/III Directives1.

Among the broad learning areas were:

  • enhance MHI regulatory regime in Singapore
  • coordinate efforts and promote cooperation among MHI stakeholders
  • drive MHIs to manage overall HSE risks in a more holistic manner
  • challenges faced by stakeholders in implementing Seveso II/III Directives

The Major Hazards Department (MHD) was established in September 2016, as a joint-government department led by MOM and comprises officers from MOM, National Environment Agency (NEA) and Singapore Civil Defence Force (SCDF). MHD’s objective is to be a single regulatory front for Safety Case assessment and site verifications.

The key activities for the Safety Case are:

  • Pre-receipt meeting

Alignment of company’s approach to develop Safety Case

  • Submit Safety Case

Receive MHD’s conclusions of the Safety Case assessment

  • Act on Safety Case conclusions

Risk controls described in Safety Case are implemented, action items in Proposed Intervention Priorities (PIP), Intervention Plan (IP) and Revision Plan (RP) are completed

  • Review Safety Case

Significance of changes in the workplace on the prevention and mitigation of major accidents is assessed; risks arising from changes are addressed

Note 1: In Europe, the catastrophic accident in the Italian town of Seveso in 1976 prompted the adoption of legislation on the prevention and control of such accidents. The so-called Seveso Directive (Directive 82/501/EEC) was later amended in view of the lessons learned from later accidents such as Bhopal, Toulouse or Enschede resulting into Seveso-II (Directive 96/82/EC). In 2012, Seveso-III (Directive 2012/18/EU) was adopted taking into account, amongst others, the changes in the Union legislation on the classification of chemicals and increased rights for citizens to access information and justice.

PCS’ journey

PCS’ journey began in September 2016, with the formation of the Safety Case Development Organisation, comprising the Safety Case Steering Committee, headed by General Manager (Plant), Er. Lucas Ng HK, and Workgroups to handle Bow Tie/ALARP and Quantitative Risk Assessment (QRA).

At the onset, PCS’ Management vision was to develop the Safety Case wholly with internal resources, and only drawing on the expertise of a consultant for the QRA. Even so, PCS members were actively involved in the QRA process, providing feedback and interacting with the consultant.

The first step was in developing competency and capability in Safety Case. All the members of the Safety Case Development Organisation went through the Safety Case Knowledge-Building Workshop and Safety Case Practitioners Workshop, organised by SCIC. In addition, specific skills workshops were organised internally (facilitated by subject matter experts) for Bow Tie and ALARP demonstration.

Bow Tie method is a risk evaluation method that can be used to analyse and demonstrate causal relationships in Major Accident Scenarios (MAS). The method takes its name from the shape of the diagram, which looks like a bow tie. A Bow Tie gives a visual summary of all plausible accident scenarios and identifying control measures to control those scenarios.

At the core of ALARP is the concept of “reasonably practicable”, involving weighing a risk against the trouble, time and money needed to control it. ALARP describes the level to which workplace risks are controlled.

PCS’ Safety Case development schedule

The schedule for the development of the Safety Case was first formulated in September 2016, with target completion in September 2017, as indicated by MHD for those companies considered under “Phase 0”. With PCS being informed later on that its Safety Case is due in September 2018 (Phase 2), more time was available to spend on further reviewing documentation, including preventative and mitigative actions.

This has allowed PCS to be better prepared for the Safety Case Pre-Receipt Meeting on 7 March 2018, the first engagement session with MHD.

At the Pre-Receipt Meeting at MOM’s premises, PCS was represented by the full-force of the Steering Committee, led by HSE Manager. PCS presented the workflow from identification of Major Accident Hazards (MAH) and Major Accident Scenarios (MAS) up to the selection of Safety Critical Events (SCE).

MHD noted the good presentation in PCS’ sample write-up on accidents/incidents reviewed and the actions taken. MHD also noted that the ALARP demonstration was organised and structured, including consideration of “what more can be done” and how a simple benefit-effort assessment was done to arrive at an informed decision to accept or reject a risk reduction measure.

MHD acknowledged that PCS’ preparation (at that time) was already at an advanced stage and noted the bulk of the work was done with its own resources. There was initial apprehension from MHD, but PCS members, as a team, demonstrated what PCS is capable of. MHD was impressed with PCS’ organisation and schedule, and emphasis that the Safety Case written presentation serves as knowledge retention and for succession planning.

Subsequent step was to proceed with the rest of the Bow Tie and ALARP for the SCEs (after MHD endorsed PCS’ methodology) and tidy up the documents, in preparation for the complete written presentation submission by the deadline of 1 September 2018.

Not wanting to cast doubts on PCS’ capability, as some companies requested for extension of their deadline, members worked feverishly to ensure all required documentation have been compiled and the written presentation is, to the best knowledge and effort, essentially complete. The submission of PCS’ Safety Case to MHD was on 27 August 2018, consisting of 2 nos. Main Document files and 6 nos. Appendix files, plus a CD-ROM of the contents.

Following the submission, MHD requested for an Early Predictive Screening (EPS) visit on 12 February 2019. This is an additional phase, inserted later on, to discuss on predictive aspects and technical demonstration, and whether PCS’ Safety Case have provided sufficient information with respect to technical areas to make the necessary demonstration, as MHD noted that some companies were not fully prepared for the On-Site Verification (OSV) phase.

The penultimate phase was the On-Site Verification, which took place on 10 & 11 April 2019. At the conclusion of the meeting, most of the observations and recommendations that MHD made were not critical to PCS’ Safety Case. These can be deferred to future Intervention Plan, targeted yearly, although may be less frequent depending on MHD’s workload.

At that meeting, MHD mentioned that one of the things they look out for is “workforce participation”, and in this area, PCS passed with flying colours. PCS group of 28 members, led by GM (Plant) surpassed their largest group of 16. They also thanked PCS for the smooth flow of the OSV and the cooperation from all involved. GM(Plant) mentioned that it is part of PCS’ culture of open-sharing, and joint “learning journey” with MOM.

Licence to continue operation

The culmination of two and a half years’ worth of effort was in the final phase, where a Conclusion Meeting was held on 12 June 2019. The meeting, more of a formality, as PCS have accepted MHD’s Intervention and Revision Plans, signalled the completion of the Initial submission of the Safety Case written presentation.

MHD’s Director, Er. Go Heng Huat, noted PCS submitted its written presentation ahead of the deadline, and was well prepared. MHD noted PCS’ emphasis and attitude on ownership of the Safety Case, “if I think of good attitude, I will think of PCS”, quoting MHD’s Deputy Director, Ms. Jaime Lim. MHD was also impressed with PCS’ approach to Human Factor/Task Analysis, which no other company, to date, have demonstrated.

With this, the next lap has begun, which is, ensuring the Safety Case Written Presentation remains a “live document”, valid and reflecting current situation. The document is also to be used as knowledge management and retention, and competency development.

It is with this in mind, GM(Plant) had the foresight to develop a sustenance framework, with options to ensure the documents are not left on the shelf to gather dust.


The Safety Case was completely developed and prepared with inhouse resources and expertise. The only exception being the QRA. PCS Management believes in total ownership of the Safety Case, and have, from the start, planned to develop with in-house resources. There were no additional resources, and all personnel involved in the Safety Case hold their own roles and responsibilities within the company.

Within each Safety Case element, a core group of the Function’s staff, consisting of engineers and operational staff, work and contribute to that element.

Management believes such hands-on involvement serves well to develop its own workforce, to not only appreciate the hazards and scenarios, but also their consequences. Aside from these, the compilation of these documents also serves as knowledge retention and succession planning.

Functions use relevant portions as awareness and refresher training, in developing and sustaining staff competency. In dispelling complacency, and the culture of chronic unease, the portions on past incidents and learning lessons, are being used.