Functional Safety 2014

continuously evolving process pressures and demands in addition to ensuring the installed SIS

continues to provide its designed-in functional safety.

In doing so, the operators must fully understand the function the SIS serves as part of the basis of

safety for the operation and its relative role in both normal and abnormal operating situations, such as

what to do when it initiates a shutdown; and how to react to diagnostic alarms from SIS Components.

The plant maintenance team plays a pivotal role to provide operators with an SIS that performs to its

targeted function and integrity and thus ensures safe operation of the plant. Management therefore

have a critical role to play in balancing the profit vs. safety equation. Everyone will appreciate that good

safety is good business for maintaining profitable and sustainable business operations.

This paper will discuss and review the challenges that are presently in place when operating,

maintaining and modifying the SIS in a pragmatic way and in accordance with the overall O&M phases

of the Safety Lifecycle as defined by IEC 61508 & IEC 61511.

The Operational Challenge

1.1. Introduction

The North Sea offshore sector is a vibrant business area with major reserves of liquid oil and natural

gas. The UK oil and gas industry benefits our lives in many ways. Its products underpin modern society,

supplying energy to power industry and heat homes, fuel for transport etc. Since first production in the

1960s, the UK offshore oil and gas industry has continuously grown and remains the country’s largest

industrial investor, paying more tax into Exchequer than any other corporate sector.

In terms of scale, the UK upstream oil & gas supply chain generated turnover of more than £35 billion

in 2012. Many companies operate within the sector including, but not limited to, the following major

business entities:

Nexen

Total

ConocoPhilips

Talisman

Shell

Maersk

TAQA

Centrica

To support the sector, many supply chain partners seek to continue to expand their industrial solutions

for the hydrocarbon supply chain, encompassing production, processing, transportation, storage and

distribution.