Safety task analysis

So, how does one ensure that adequately trained workers are performing their assigned tasks safely There are no guarantees, but a good step is to have a qualified person perform a job safety analysis. The job safety analysis (ISA) has taken on many names over recent years. Some people refer to safety task analysis (STA), job hazard analysis (JHA), or other names. In this book, this useful tool is simply referred to as a ISA. 

Specific titles within each of the operating phases can be determined using a job task analysis in concert with the technology package and process safety information. Appendix D, ISD Model and Job Task Analysis Techniques, provides basic guidance in this useful method. 

An example of procedures found by performing a job task analysis would be rework procedures. Occasionally, out of specification product is produced which can be reworked in the process. This subcategoiy of normal operations phase procedures may require special consideration. While rework can be a straightforward operation, it could have safety consequences if done improperly. 

At this point, a task analysis is performed. A "task" is defined as an activity oi performance (hat the operator sees as a unit either because of its performance character]stic.s or becau.se that activity is required as whole to achieve some part of the system goal. Only the tasks that are relevant lo the system safety are considered. A task analysis involves decomposition of each task into individual units of behavior. Unusually, this analy.sis tabulates information about each specific human aciiun. The format of such a table is not rigid - any style that allows easy retrieval ot the information can be used. The format reflects the level of detail and the type of task analysis performed. The analysis yields... 

Human Factors Engineering/Ergonomics approach (control of error by design, audit, and feedback of operational experience) Occupational/process safety Manual/control operations Routine operation Task analysis Job design Workplace design Interface design Physical environment evaluation Workload analysis Infrequent... 

This section illustrates how the techniques described in Chapter 4 can be used to develop a procedure for the job of the top floor operator in the batch plant considered earlier. Two techniques are illustrated (i) a hierarchical task analysis (HTA) of the job, and (ii) a predictive human error analysis (PHEA) of the operations involved. HTA provides a description of how the job is actually done while PHEA identifies critical errors which can have an impact on the system in terms of safety or quality. The basic structure of the procedure is derived from the HTA which specifies in increasing detail the goals to be achieved. To emphasize critical task steps, various warnings and cautions can be issued based on the likely errors and recovery points generated by the PHEA. 

Kirwan B., 1998b. Safety management assessment and task analysis - a missing link , in Hale et al. (Eds ), Safety Management the challenge of change, Pergamon, Oxford. 

Task C - Safety and Analysis for Writing of Codes and Standards... 

The human factors literature is rich in task analysis techniques for situations and jobs requiring rule-based behavior (e.g., Kirwan and Ainsworth 1992). Some of these techniques can also be used for the analysis of cognitive tasks where weU-practiced work methods must be adapted to task variations and new circumstances. This can be achieved provided that task analysis goes beyond the recommended work methods and explores task variations that can cause failures of human performance. Hierarchical task analysis (Shepherd 1989), for instance, can be used to describe how operators set goals and plan their activities in terms of work methods, antecedent conditions, and expected feedback. When the analysis is expanded to cover not only normal situations but also task variations or changes in circumstances, it would be possible to record possible ways in which humans may fail and how they could recover from errors. Table 2 shows an analysis of a process control task where operators start up an oil refinery furnace. This is a safety-critical task because many safety systems are on manual mode, radio communications between control room and on-site personnel are intensive, side effects are not visible (e.g., accumulation of fuel in the fire box), and errors can lead to furnace explosions. 

CSGs (Constructive Solid Models), 182 C/S systems, see Client/server systems CTA, see Cognitive task analysis CTDs, see Cumulative trauma disorders CTP (capable-to-promise), 2046 CTS, see Ctupal tunnel syndrome Cuban Missile Crisis, 139 Culture. See also National culture Oigemizational culture and eilignment of technology/oiganizational structure, 956-961 safety, 959-961 Culture shift, 14, 16 Culture systems, 15-16, 1798 Cumulative distribution function (CDF), 2385-2386... 

Ramsey, J. R. (1985). Ergonomic factors in task analysis for consumer product safety. Journal of Occupational Accidents, 7, 113-123. 

Postdevelopment Analyzing well-defined tasks performed by an operational system provides a detailed description of task procedures and resource requirements that can be used to improve task performance and the system design. For example, Rogers et al. (2001) were able to reveal many sources of errors and design recommendations from their task analysis of a consumer blood glucose meter. Suri (2000) used task and user analyses of an existing defibrillator to identify errors and safety concerns, and as a basis for a new design. 

Job descriptions/task analysis/job safety analysis (if available) for all operator jobs Process unit emergency response plans (if available)... 

What is needed is an integrated ergonomics task analysis system that addresses productivity, cost efficiency, safety, and sometimes quality — all in one study. That would be unique. In support of that idea, consider these excerpts from the web page for ergo web, taken from a January 2001 entry quoting Dr. Peter Budnick, a professional ergonomist and CEO of ErgoWeb ... 

In Management Guide to Loss Control, by Frank E. Bird, Jr., a chapter on Proper Job Analysis and Procedures extends the purposes of a task analysis to include aspects other than safety. Bird said ... 

For information on task analysis that incorporates all aspects of work, see Task Analysis For Productivity, Cost Efficiency, Safety and Quality, a chapter in my book Innovations in Safety Management Addressing Career Knowledge Needs. 

I suggest that safety professionals give task analysis a greater emphasis as a qualitative predictor of the probability of hazards-related incidents occurring. Task analyses are to define hazardous or inefficient work procedures. 

If a safety professional really wants to know what hazards may create problems tomorrow, task analysis is a highly effective way to identify them. Of course, the process would culminate in proposals for the appropriate preventive actions. The ancillary benefits are considerable, since many people can be trained through the task analysis process to identify hazards and how to seek their elimination or control. 

Using the task analysis as a starting point, the System Safety Engineer can assist (via Step 3) the HF specialist to identify feasible types of error in the task and record the possible consequences of the error, and the safeguards and recovery mechanisms in place to prevent/detect/correct them. Be explicit in the recording of any assumptions (e.g. escalating or containing factors) which influence decisions made. 

The Nominal Task Analysis was linked to the risk assessment analysis for the critical scenarios identified as relevant to the case study while the hnk between the safety barriers and the activities identified in the task has been also estabhshed. Additionally the task analysis has been used to describe in detail the actions connected with a specific safety barrier related to a relevant accidental scenario and the mode the latter can be represented in the VR experiments. 

Deviations are in fact analysed for all the activities identified as critical (as being part of a safety barrier) according to the bow-tie analysis of the accidental scenarios. Every step considered to be critical and therefore represented more in depth in the detail task analysis is associated with the Ust of relevant PSF affecting it for the scope of experiment design. 

The Human Factors analysts needed an approach and a tool to help them in providing a template for the interview process of a Task analysis with the ability to structure the interview phase in order to highlight and examine the deviations from standard practice. These deviations are fundamental to understanding what can and does go wrong in the field and should be an integral part of any safety critical task representation. A graphical representation of the procedure map linked to the template including ... 

The issue related to this UML modeling tools is that its usage for Human Factors Practitioners and Safety analysts is not so immediate because it is meant to be used primarily by software developers. Furthermore no support is provided for guiding the task analysis interview process. 

A safety analyst / HF specialist performs a task analysis interview sessions in real time by filling the interview template or the tabular task ... 

Inoue, S. Aoyama, H. Kageyama, K. Furuta, K. 2005. Task Analysis for Safety Assessment in En-Route Air Traffic Control. In Proc. 13th Int. Symp. on Aviation Psychology, Oklahoma, USA, April 2005 253-258. 

A typical system safety task for hazard identification would be the preparation of a preliminary hazard list (PHL). Hazard identification or discovery is accomplished by reviewing lessons learned, accident reports, and other historical data. A PHL may be prepared through an informal conference, the use of checklists, and occasionally other techniques such as energy trace and barrier analysis (ETBA). 

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