Audit Interview Sampling

Before a company can proceed with a COR audit, they must complete and submit a Notice of Audit (NOA) to SafetyDriven – TSCBC. The main function of the NOA is to formally initiate the audit process.

The most important section of the NOA is the “Audit Sampling Plan” on page three. The Audit Sampling Plan instructions read: “Please provide information on intended sample size and site selection. List all sites, whether sampled or not.”

You may have wondered, why does SafetyDriven – TSCBC need this information?

This part of the audit is what we call the audit scoping. We need to know the company’s “operational details”. The details of interest are the number of worksites and the number of employees (managers, supervisors, and workers).

One of the main criteria of the COR audit is that all worksites must be audited over the three year audit cycle. In order for us to determine if a company is meeting this criterion, we require all worksite locations to be disclosed on the NOA form each year. In addition to detailing all of the worksites, the auditor checks off the worksites they intend to audit that year and we compare that to the selections of the previous years to ensure all worksites will be audited over the three-year period.

tech smallThe other main part of the audit scoping relates to the number of employees the company has in BC. Some companies have thousands of employees nationally or internationally, but for BC COR we are only interested in the BC employee count.
The NOA form audit-sampling plan has a section for the auditor to disclose the number of managers, supervisors, and workers to SafetyDriven – TSCBC. It also has a section where the auditor indicates how many managers, supervisors, and workers they intend to interview as part of the audit process. Once they have submitted that, we review the two sets of numbers and determine if the interview sample size they intend to follow is appropriate for the operational details of the company.

How do we do that? Mostly, we use a representative interview sample chart. The top five lines of our sampling chart looks like this:

Number of work force Minimum number of interviews Number of work force Minimum number of interviews
1 to 4 All 231-233 34
5 4 234-240 35
6 – 7 5 241-249 36
8 6 250-299 37


The chart extends up to 550 employees, and we have another chart that extends up to 25000 employees, just in case. Hey, you never know…

So there it is. The auditor submits the company’s operational details and we review them for conformity to the rules. If we discover a problem with the auditor’s proposed scoping, we suggest an amendment and have them revise and resubmit. We continue to work with the company, typically via email, until the scoping is right. Once the scoping is right, we approve the audit and the auditor can begin the rest of the COR audit process for that year.

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