Best Practices in Risk Based Safety Studies Methodology - Impact on EPC Project Cost and Schedule.
Authors: Aldhaheri Shamsa , Jha Ajay , Singh Harendra , Kamal Faris , Takieddine Oussama 
Published: November 2019

Abstract

Objectives/Scope
This paper is intended to discuss the impact of Safety Studies methodology on EPC Projects execution. The Specialized Safety Studies are normally carried out by Third Party Consultants and managed by EPC Contractors. In most of the fast tracks projects where Safety Studies should not take more than 6-8 months, EPC Contractor’s face challenges when methodologies for performing these studies are not practical to accommodate on fast track Projects norms.

Methods, Procedures, Process
EPC Contractor’s experience and lessons learned based on management of various third party studies are outlined hereafter.
EPC Contractor studied different cases where software requirement, basis & assumptions, methodologies or approaches suggested by Operating Companies, change or become impractical to implement during EPC or Detailed Engineering Phase. EPC Contractor analyzed its effect especially on fast track projects delivery, execution, cost and ability to adopt design changes that may come as a result of Safety Studies recommendations. Moreover, EPC Contractor looked deeply into the lack of dedicated Project Management Consultant (PMC) for the whole EPC Project execution period and impact thereof.

Results, Observations, Conclusions
EPC Contractor’ detailed analysis shows that there is substantial benefit for EPC Contactors and Operating Companies in terms of cost and schedule. Based on lessons learned on various EPC projects executed, the following as minimum is observed:
In the case of CFD Smoke & Gas Dispersion Study, Operating Companies wish to simulate similar number of dispersion cases rather than logical adoption of liquid pool fire cases. For CFD Explosion Study, production of cruder explosion exceedance curve is required rather than scaling and correlation of dispersion and explosion runs. Also, for CFD based Safety Studies, it is observed that refined grid approach is requested instead of practical grid values based on EPC Contractor experience. ALARP demonstration is imposed for impairment frequencies between 1×10-5/yr. and 1×10-4/yr. rather than a criterion of 1×10-4/yr. for HSECESs.
The above becomes challenging and increases simulation time significantly. On the other hand, similar results achieved by following practical approaches. Contractor experienced negative impact on progress as a result of not having permanent PMC Engineer which delays approval of deliverables. Contractor suggests that methodologies should be set and agreed during FEED and remain unchanged during EPC for proper cost estimation and execution of Projects.

Novel/Additive Information
EPC Contractor’s case studies and lessons learned can be adopted as best practices for fast track schedule driven Projects. Real project case studies demonstrate challenges faced by EPC Contractor in managing overall EPC Project execution as a result of Safety Studies methodologies. The paper highlights the benefits with various case studies that return many benefits to both Operating Companies and EPC Contractors.