Safety performance measurement Categories

Each of the safety performance measurement methods can be characterised as a combination of the following three facets (a) data source (b) identification procedrrre and (c) data category. Typical data sources for safety performance in healthcare are patient case records, incident reports, field data (for example, obtained by observation), and self-reported data (typically elicited by the use of a questiormaire or interview). 

Commonly used descriptive statistics include measures that describe where the middle of the data is. These measures are sometimes called measures of central tendency and include the mean, median, and mode. Another category of measures describes how spread out the data is. These measures are sometimes called measures of variability and include the range, variance, and standard deviation. Additional descriptive measures can include percentages, percentiles, and frequencies. In safety performance measurement, the safety professional must determine the format of the data (i.e., ratio, interval, ordinal, or categorical) that will be collected and match the data format to the appropriate statistic. As will be discussed in the following sections, certain descriptive statistics are appropriate for certain data formats. 

This category of injury is used because this is the degree of injury that is mostly recognized in the safety profession. This injury classification is what safety campaigns, safety records, safety performance measurement, safety comparisons, safety competitions, safety recognition schemes, etc., recognize as being the accepted measurement of safety. If less than 1 percent of serious injuries are caused by accidents, safety efforts should not be focused only on them. More effort should be directed at... 

Performance measurements are grouped into two categories qualitative and quantitative. Qualitative safety measurements include checklists and narrative evaluations from accident report forms. Quantitative performance measures include any performance measures to which a number can be assigned. Measurement is crucial to achieving excellence in safety from two broad standpoints (Petersen 1998) ... 

Once the observations have been recorded, the data will be added to arrive at a total number of behaviors for each category. In this example, there were a total of six safe behaviors and two at-risk behaviors observed. Of the eight total behaviors that occurred, it was found that six were considered to be safe, so this task measured as 75% safe. Rather than focusing on failures, such as are measured by injury rates, this metric provides a proactive positive measurement of safety performance. Observations can be accumulated in a database or spreadsheet and measured over time with the goal of increasing the level of safe performance of jobs that occur. 

In the second category, specific system safety performance requirements were elicited through the review of mitigations/protection measures in the hazard log. Those mitigations/protection measures that are related to novel equipment, or new processes, or any novel environment states within which the conventional equipment or a process is to operate, were converted into safety requirements. Those safety requirements that are related to novel equipment were further analysed in order to facilitate the representation of these in the QRA, either as base events or logical gates. 

Every month, SMS measures the previous 24 months of roadside violation and crash data performance and calculates a score in the seven Behavior Analysis and Safety Improvement Categories (BASICS). 

Performing JSAs is a complex process. To better understand the importance of this analysis tool, figure 9-7 shows a completed JSA for hydraulic line replacement. Please note accident categories described in the potential hazards section. These potential hazards will aid in determining what safety measures and personal protective equipment are necessary for a given job. 

Safety Measurement System (SMS) is a tool for assessing available roadside performance data. These data are used to rank entities performance relative to their peers in any of six Behavior Analysis and Safety Improvement Categories (BASICs) as well as crash involvement (Crash Indicator). Rankings within these BASICs and the Crash Indicator will be used by law enforcement to select entities for appropriate interventions... 

In system safety, when an HA is performed, the outcome of an identified hazard is the expected damage that would result when the hazard transforms into a mishap. Damage, or damage effects, is typically measured in terms of death, severity of injury, functional and physical loss of a system or product, and/or the monetary losses incurred. MIL-STD-882 provides a method for categorizing the amount of damage by severity categories or levels. 

Validity relates to whether you are measuring what you want to measure. When we measure the width of a room, the question of validity usually does not arise. When we are measuring a complex process, such as aptitude to perform well in college or the ability of the safety-management system in a plant to prevent future loss, validity becomes a serious question. Scientists (Chronbach and Meeh 1955) generally define three categories of validity content-related, criterion-related, and construct-related validity. 

The safety/risk criteria. The safety/risk criteria establish the top-level system safety requirements, or objectives. Regulatory authorities may have different definitions for the various categories of hazards/accidents. To be able objectively to distinguish and evaluate the various hazards present, it is important to define the exact terminology and to allocate a measure of performance. This is an important (and arguably most neglected) topic as it is the safety acceptance criteria the system is expected to achieve, and hence the measure (or standard) the assessment will compare the system against. For more detail on safety criteria, see Appendix B. The system level. Define the systems level at which safety is to be assessed. The importance of this step is explained in Section 8.3 above. A safety assessment by a supplier of a component (e.g. a flare dispenser) will vastly differ in scope and approach to a safety assessment for a product (e.g. an aircraft) or user system (e.g. a facility). 

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