Welcome to the 9th article in the series. Article 8 overviewed the selection of critical controls, hopefully generating some thoughts about setting company or site objectives for moving to CCM, as well as considering the concept of ‘indicativeness’ as a potential critical control requirement.
Critical control?
This article will continue with the critical control selection topic by expanding on the measurability and indicativeness of control acts that might be potential critical controls. As mentioned previously, acts are one type of control along with objects and technological systems.
Feedback on article 8 suggested that climbing onto a large vehicle or structure using 3 points of contact is an act, and possibly a critical control if the company or site defines their priority unwanted events as single fatality consequences or higher.
Many mining equipment manufacturers have done major work to reduce precarious climbing onto or off equipment, but the need remains for people to climb at heights with 3 points of contact.
So, can this act of climbing potentially be a critical control? Is it crucial, measurable and indicative?
A generic company or site Bowtie Analysis for a fall from some defined height (possibly 1.5 m or more) would likely result in ‘climbing using 3 points of contact’ as a control act for many of the related threats and possibly the sole control for some. Thus, the act could be seen as crucial.
Initial consideration of the acts ‘indicativeness’ may also suggest its’ value as a critical control. A crucial act that is common across many threats should be indicative. However, the other part of the critical control discussion is measurability.
To be indicative of the overall fatal fall risk the act must be measurable. How do we measure this crucial, indicative act to gauge the effectiveness of controls and thereby the acceptability of the company or site fall risk?
In article 8, the limitation of direct act observation was mentioned. In mining, it is often difficult to gather observation data on climbing. However, there may be related erosion factors and supporting activities that are possible measures of the likelihood that a person will use 3 points of contact when climbing.
Act effectiveness
An act has a life cycle like an object. The act must be defined, documented, transferred to the persons that are expected to act, and assessed to ensure the act is understood. Acts are also reinforced and modified to ensure they are up-to-date. Effectiveness of the steps in the act life cycle will affect the likelihood that the act will occur when required. This is how procedures, training, and communication contribute to acts’ effectiveness. As such, these aspects become part of an overall multifactorial ‘algorithm’ for the effectiveness of an act that can also include any available direct observation data.
In addition, and also mentioned in article 8, data related to the initiatives intended to reduce identified major erosion factors or to reinforce important supporting activities might also be part of an act algorithm.
The effectiveness of an act that is believed to be critical, like the 3 points of contact example, can be established with adequate accuracy but the data used to verify the level of effectiveness will be sourced from multiple sources. Direct observation data about the act may only be part of the measure.
Another approach to considering act effectiveness contributors can be found in human error causation such as the work of Geoff Simpson and Tim Horberry as provided in the illustration below from their book “Understanding Human Error in Mine Safety” (2009).