combining hazop and sil

A division of ACM Automation Inc

March 10th, 2004 Pg1

HAZOP & SIL Analysis – Time & Cost Comparison Traditional vs. Integrated SilCoreTM Approach Using the right methodology and tools, the time and cost of conducting Hazard and Operability (HAZOP) and Safety Integrity Level (SIL) Analysis can easily be reduced by 30%, with a significant improvement in overall data integrity and manageability. Summary Traditionally, a HAZOP and SIL Assessment (either using the Risk Graph or LOPA methodologies) are two separate facilitated sessions, which produce two unique databases. SIL Validation is yet a third task that uses another set of tools and produces a third database. ACM has developed an integrated approach using a sophisticated HAZOP / SIL tool, called SilCore™ that combines these three tasks into one tool and one database. In the Integrated Approach, only one facilitated session is required for HAZOP and SIL Assessment. Only one database is created, and it is used to perform SIL Validation. In addition to being a secure and auditable database, this single database is also part of a complete “handover package” that operators need to ensure they

maintain the SIL integrity assigned to each SIL loop. The benefits of the Integrated Approach are: Minimum 30% savings in time and costs A single auditable database is used for both

the HAZOP and SIL Assessment/Validation Mathematical errors during SIL Validation

are eliminated A complete electronic handover data

package can be provided to Operations Operators can easily model proposed

changes to their maintenance and testing plans (SIL Optimization) using the same database

Silcore LOPA assessment detailed



A – The Problem The adoption of the IEC 61511 standard Functional Safety – Safety Instrumented Systems for the Process Industry Sector has introduced a new challenge into engineering projects. Specifically: How do I determine if my project requires a

Safety Instrumented System? If it does, how do I integrate the design,

implementation, maintenance and operation of Safety Instrumented Systems into the project?

With the HAZOP methodology being so commonly used on larger capital projects, one of the issues facing EPCs is how to plan and execute projects where both HAZOP and SIL Analysis is called for. While the HAZOP practice is well established within most organizations, dealing with the relatively new SIL Analysis requirement is more problematic. Firstly, many SIL practitioners use a combination of tools to conduct SIL Analysis, including Excel spreadsheets, off the shelf SIL Assessment and Validation tools and homemade programs. Too often the result is unlinked and disjointed sets of data in several files that are of dubious integrity and frustrating to manage. Additionally, after working with many EPC and Operating Company clients, we also know that Operators are struggling with how to maintain the SIL rating that the EPC designed into each SIL Loop.

B – The Options Traditional Approach – The traditional approach to performing HAZOP and SIL Assessment studies is to treat them as separate tasks. First, a team of experienced engineers, operators and maintenance staff, led by a traditional PHA facilitator, performs the HAZOP. They identify hazards and use a risk matrix to rank the hazards, documenting the study either on a MS-Excel spreadsheet or with PHA software (i.e. PHA Works, PHA-Pro). At a later date, a second meeting is convened to complete the SIL Assessment. Traditionally, many users choose the Risk Graph approach, though more companies today are increasingly adopting the Layer of Protection Analysis (LOPA) methodology. A multi-disciplinary team, led by an experienced SIL facilitator completes the SIL Assessment. Usually a MS-Excel spreadsheet is used to document the study. Finally, a third exercise called SIL Validation is then conducted using a different set of tools and databases. Output information from the SIL Assessment is manually inputted into these tools to perform the SIL Validation. The result of this three-phase exercise is typically three databases containing three different studies. In the end, in addition to the extra cost and considerable hassle and frustration of again mobilizing a team for the SIL Assessment, maybe even the same group as for the HAZOP, you’ve also got to wrestle with three databases. Attempting to manage the SIL Assessment and Validation process with separate databases becomes time consuming, vulnerable to errors and expensive to maintain.

Integrated HAZOP/SIL Approach with SilCore™



The integrated HAZOP / SIL approach looks at the HAZOP and SIL Assessment as one task and involves one meeting where a multi-disciplinary team, led by an experienced facilitator who understands not only Hazard Assessment but SIL Analysis and Risk Mitigation. The LOPA process is selectively applied to those risks identified during the HAZOP as being unacceptable. By using a comprehensive software tool called SilCore™, all details of both the HAZOP and SIL Assessment are captured in one database at one meeting and the SIL Validation phase of the project can proceed seamlessly using an IEC 61511 compliant software tool. There are two keys to realizing time and cost savings:

Using a skilled facilitator who knows how to

lead HAZOP and SIL studies? Using a robust tool like SilCore™ to record

the study.

The real savings come in being able to reduce the number of multi-disciplinary team meetings from two to one, and in having the HAZOP / SIL Assessment data in the SilCore™ tool, where it can easily be accessed and manipulated as part of SIL Validation. In addition, EPCs also have the capability once the SIL Validation is complete to handover the electronic data files in a format that the Operating Company can use to manage the SIL Loop over its life within the project. SilCoreTM addresses the need for one integrated tool that can be used by EPCs during the engineering design phase and Operators after the project is commissioned. With a Microsoft SQL database as its engine, the SilCoreTM database is unlimited in its capacity to process SIL Loop configurations, and provides an auditable process that assists in meeting ISO and Quality Management practices.

Silcore validation detailed



Benefits of the Integrated Approach 1- Cost Savings of 30% Comparing the total costs of the Traditional vs. Integrated Approach to conducting HAZOP and SIL studies provides one measure of the value of SilCore™ and the Integrated Approach.

Scenario - Assume that your project requires 5 days of HAZOP facilitation. Also assume that a full SIL Analysis (Assessment and Validation) must be performed on 20 SIL loops. Table 1 below shows that significant time savings can be realized by using SilCoreTM.

Lifecycle Stage Phase Traditional Way Using SilCoreTM

Preparation Facilitated Session Reporting

3 days 5 days 2 days

3 days 5 days 2 days HAZOP

Total HAZOP Time 10 days 10 days

SIL Assessment Preparation Facilitated Session

3 days 5 days

2 days 2 days

SIL Validation Calculations 9 days 5 days

HAZOP / SIL Report Report 3 days 2 days

Total SIL Time 20 days 11 days Total Elapsed Time 30 days 21 days

Table 1 – Total Elapsed Time to Complete HAZOP / SIL Analysis

Basis 20 SIL loop study Team Meeting Costs Savings Alone Pay for SilCoreTM In addition to completing the project 30% quicker, the total meeting costs for the HAZOP and SIL using the Integrated Approach are 30% less.

If one considers the multi-disciplinary team facilitation time needed for team members to be together for the HAZOP and SIL Assessment phase can be cut significantly, the resulting team meeting cost savings to clients by using SilCoreTM more than pays for the cost of the software. See Table 2.



Traditional Way SilCoreTM Savings HAZOP SIL Assessment

5 days 5 days

5 days 2 days

Total Elapsed Time 10 days 7 days x 6 team members x 6 team members Total Team Time 60 Man days 42 Man days @ $650 / day @ $650 / day Total Team Cost Travel & Rooms*

$39,000 $18,000

$27,300 $12,600

Total Meeting Cost $57,000 $39,900

$17,100 * Based on average of $300 per Man day

Table 2 – Cost to Complete HAZOP and SIL Assessment

2- SIL Loop Maintenance Fast and Easy For Operating Companies, SIL Optimization time savings are even more significant, as the process of testing and maintaining SIL Loops is reduced from an 8 hour exercise to 1 hour. This is due to having only one data base and SilCore’s™ capability to model an unlimited number of scenarios almost effortlessly.

3- One Auditable Database Using SilCore™ to document the studies means a permanent record of the HAZOP study and all SIL loop modifications always exists in one data base. This is critical for companies who have a Management of Change practice that requires documentation and auditability.

4- Eliminates Mathematical Errors SilCore™ uses a sophisticated calculation engine that instantaneously computes Probability of Failure on Demand (PFD) totals during SIL Validation using the IEC 61511 standards. This eliminates the possibility of errors, which often go undetected and provide false conclusions. 5- Enables Electronic Handover of SIL Data Having the capability to handover a comprehensive electronic data file will be welcomed by EPCs and Operating Companies alike, as it eliminates the rework and confusion that often exists currently.

ACM Facility Safety 906-12th Avenue SW, Suite 825 Calgary, Alberta T2R 1K7 Canada Tel. +1 403 264 9637

For more information about SilCore™ please contact

Mr. Murray J. Macza, VP Sales & Marketing

[email protected] orvisit our website www.acm.ab.ca

combining hazop and sil

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