please read the attached files for needed work
4/2/2020 Elective Module B: The Risk Matrix: SRA 311, Section 002: Risk Analysis, SP20 Howerton WC https://psu.instructure.com/courses/2043139/pages/elective-module-b-the-risk-matrix?module_item_id=28203354 1/2 Elective Module B: The Risk Matrix For this module, you are asked to consider the risk matrix as a tool for risk assessment. Your response to this module should be packaged as a single PDF file that addresses the questions below. Resources for this module include the following: The Internet PAPER: What's Wrong with Risk Matrices? (https://psu.instructure.com/courses/2043139/files/105770586/download?wrap=1) Article: What's Right with Risk Matrices? (https://psu.instructure.com/courses/2043139/files/105770624/download?wrap=1) (https://psu.instructure.com/courses/2043139/files/105770624/download?wrap=1) PAPER: Designing an Effective Risk Matrix? (https://psu.instructure.com/courses/2043139/files/105770570/download?wrap=1) Video: Why Most Risk Assessments are Wrong if not Dangerous (https://www.youtube.com/watch? v=PA9rqNBZWIw) Minimize Video PAPER: Further Thoughts on the Utility of Risk Matrices (https://psu.instructure.com/courses/2043139/files/105770591/download?wrap=1) 1. Do some Internet sleuthing to learn all you can about the "risk matrix." Copy and past no less than five example risk matrices that you encountered online. 2. Describe what a risk matrix is and what it is used for. 3. Read the Cox article. What are Cox's criticisms of risk matrices? What is his general conclusion? https://psu.instructure.com/courses/2043139/files/105770586/download?wrap=1 https://psu.instructure.com/courses/2043139/files/105770624/download?wrap=1 https://psu.instructure.com/courses/2043139/files/105770624/download?wrap=1 https://psu.instructure.com/courses/2043139/files/105770570/download?wrap=1 https://www.youtube.com/watch?v=PA9rqNBZWIw https://psu.instructure.com/courses/2043139/files/105770591/download?wrap=1 4/2/2020 Elective Module B: The Risk Matrix: SRA 311, Section 002: Risk Analysis, SP20 Howerton WC https://psu.instructure.com/courses/2043139/pages/elective-module-b-the-risk-matrix?module_item_id=28203354 2/2 4. Read the Talbot article. What is Talbot's response to Cox? What is right about risk matrices? 5. What do you think? Feel free to do a pros/cons assessment. Further Thoughts on the Utility of Risk Matrices Risk Analysis DOI: 10.1111/risa.12057 Further Thoughts on the Utility of Risk Matrices David J. Ball and John Watt∗ Risk matrices are commonly encountered devices for rating hazards in numerous areas of risk management. Part of their popularity is predicated on their apparent simplicity and trans- parency. Recent research, however, has identified serious mathematical defects and incon- sistencies. This article further examines the reliability and utility of risk matrices for ranking hazards, specifically in the context of public leisure activities including travel. We find that (1) different risk assessors may assign vastly different ratings to the same hazard, (2) even following lengthy reflection and learning scatter remains high, and (3) the underlying drivers of disparate ratings relate to fundamentally different worldviews, beliefs, and a panoply of psychosocial factors that are seldom explicitly acknowledged. It appears that risk matrices when used in this context may be creating no more than an artificial and even untrustworthy picture of the relative importance of hazards, which may be of little or no benefit to those trying to manage risk effectively and rationally. KEY WORDS: Public space; reliability; risk assessment; risk matrices; utility 1. INTRODUCTION In 2008, Tony Cox wrote about serious tech- nomathematical problems associated with a widely used risk tool often referred to as a consequence- probability matrix or, more simply, a “risk matrix.”(1) Generally, these devices come in the form of quali- tative or semiquantitative instruments in which haz- ards are first identified and then allocated to a box on a two-dimensional grid for which one axis measures the likelihood of a specific incident and the other the potential severity of consequences.(1,2) The issues identified by Cox are certainly not con- fined to the United States, and indeed usage of risk matrices has spread in the United Kingdom and Europe from industry to all manner of public and private agencies ranging from hospitals to small- and Middlesex University, School of Science and Technology, Centre for Decision Analysis and Risk Management, London, NW4 4BT, UK. ∗Address correspondence to John Watt, Middlesex University, School of Science and Technology, Centre for Decision Analysis and Risk Management, The Burroughs, Hendon, London, NW4 4BT, UK;
[email protected]. medium-sized enterprises, local and central govern- ment bodies, and professional institutions. Applica- tions, besides injury control, range over environmen- tal protection, emergency planning, credit risk, and much more besides.(3–6) As further evidence of their ubiquity, if the Internet is searched for “risk matri- ces,” numerous examples are discovered with origins in many parts of the world. These range in size from 2 × 2 to 10 × 10, and come in a stunning variety of colors, but all with essentially the same charac- teristics. Our particular interest here is the applica- tion of these matrices to what might be considered to be beyond-the-workplace scenarios; for example, to hazards encountered in everyday leisure activities, including travel, countryside recreation, and in visit- ing sites of cultural heritage. The imagery of risk matrices is powerful, which may, along with their alleged and apparent simplic- ity, explain their popularity among agencies that are responsible for mainly lesser hazards,1 and therefore are likely less qualified in risk, but who nonetheless 1That is, neither major nor catastrophic hazards of the kind faced in heavy industry. 1 0272-4332/13/0100-0001$22.00/1 C© 2013 Society for Risk Analysis 2 Ball and Watt Fig. 1. Three locations. (A) A railway platform. (B) A cliff-top public footpath at Beachy Head. (C) A medieval bridge in Exeter. feel the need to be seen to be proactive in manag- ing risk. Inter alia, and as observed, though not sanc- tioned, in the new international guidance on risk as- sessment (ISO 31010),(7) it is said that matrices are also widely used to determine if a risk posed by a given hazard is or is not acceptable. We ourselves would, as discussed later, dispute the legitimacy of using matrices in this way, here particularly, because there is a further important issue that comes up in the context of leisure space and activities. This is that risk matrices, if used as quasi-decision-making tools, may inadvertently and adversely affect the public en- joyment of their leisure time through leading to the prohibition of certain things or activities(8) despite the risk being acceptable to participants, or the en- joyment of some level of risk being intrinsic to the activity. Furthermore, if decisions based on risk assess- ment and devices such as risk matrices were found to be inconsistent across public space, as Cox has in- ferred could happen through an inherent inability to order risks logically,(1) they might generate ridicule and outrage, and this is exactly what has happened in the United Kingdom where the government has instigated an inquiry(9,10) and the lead regulator, the Health and Safety Executive, has felt obliged to “re- store sanity” by publishing a health and safety “Myth of the month” feature on its website.(11) It is this latter issue, of the consistency of use of risk matrices as applied to what are normally seen as beyond-the-workplace hazards, that we explore here. A growing number of authors, highly experi- enced in risk assessment, have questioned or had cause to investigate alleged shortcomings of risk ma- trices, mainly on technical grounds.(1,2,12,13) In addi- tion, standards-setting institutions have warned of the potential for subjectivity and inconsistency,(7,14) as have researchers in occupational safety.(15) Our specific interest is to investigate the impact of sub- Likelihood Consequences Insignificant Minor Moderate Major Severe Almost certain 5 10 15 20 25 Likely 4 8 12 16 20 Possible 3 6 9 12 15 Unlikely 2 4 6 9 10 Rare 1 2 3 4 5 Fig. 2. The risk matrix used in this study. The number in each cell represents in the conventional way the product of scores (1–5) as- signed to the individual likelihood and consequence ratings. jectivity in assigning hazards to risk matrices and to reflect upon its origins. 2. METHODOLOGY Two main surveys were undertaken drawing from a cohort of international postgraduate and un- dergraduate students. The students involved were studying either risk management or occupational health and safety. In the first survey, 50 students were asked to rate each of the three hazard locations shown in Fig. 1 by assigning them a position on a 5 × 5 qualitative risk-consequence matrix (Fig. 2). In each case, attention was drawn to a specific hazard involving a fall from height. Thus, location A com- prises a small-town railway platform through which nonstop express trains pass at high speed. Location B is a much used public footpath along the top of imposing cliffs at Beachy Head in southern England. Location C is a historic venue in the form of a 13th- century medieval bridge also used as a public foot- path, and with an unprotected drop of about 5 m. Utility of Risk Matrices 3 The risk matrix deployed is typical of some of those currently used by national and international profes- sional bodies whose primary purpose is health and safety and injury prevention in particular. In the initial experiment, the three photographs and the matrix were presented to the students with brief information about the hazard sites in order that they would have free rein to define things in their own way and use their own judgment. Although sac- rificing precision in one sense, it is recognized that to uncover thought processes in decision making, re- spondents should be given as much latitude as possi- ble in order that they may express themselves.(16,17) Some of the implications of that decision will be dis- cussed below, but the purpose was to evaluate the use of such matrices by both health and safety pro- fessionals and perhaps nonspecialists such as teach- ers, youth leaders, and others who might be asked to undertake a risk assessment of a hazard, for example, as a precursor for taking parties on excursions. A second trial was conducted with a subset of 21 students at a later date. The task presented to this cohort was to review, as individuals, the risk ratings previously generated by a different group; to com- ment upon them in writing; and to produce their own rating of the three hazards accompanied with a writ- ten explanation of their choices. An important differ- ence in this case was that the participants had several weeks to consider the task and carry out their rat- ings, whereas in the first study ratings were carried out within a few minutes without recourse to further information or deep contemplation. It is felt that any potential bias from subject in- terest, experience, or previous training was likely to operate in favor of the use of risk matrices, based on their ubiquity in workplace environments. On the other hand, these students had been introduced to a number of theoretical studies that offered possible insights into variations in the way that people might use risk matrices (which we discuss in Sections 4.1 to 4.7). This second exercise thus offered the chance to examine the prevalence of the various potential ex- planations among our sample after reflection to shed light on decision making. 3. RESULTS Fig. 3 shows the individual risk ratings that were produced for each of the three hazards by the first cohort of 50 students. The most striking feature of these data