January 2011

Examiners’ Report NEBOSH National Diploma in Occupational Health and Safety - Unit A

2011 NEBOSH, Dominus Way, Meridian Business Park, Leicester LE19 1QW

tel: 0116 263 4700 fax: 0116 282 4000 email: info@nebosh.org.uk website: www.nebosh.org.uk The National Examination Board in Occupational Safety and Health is a registered charity, number 1010444 T(s):exrpts/D/D-A 1101 EXTERNAL DW/DA/REW

Examiners’ Report NEBOSH NATIONAL DIPLOMA IN OCCUPATIONAL HEALTH AND SAFETY

Unit A: Managing health and safety

JANUARY 2011

CONTENTS Introduction 2 General comments 3 Comments on individual questions 4

2 EXTERNAL

Introduction

NEBOSH (The National Examination Board in Occupational Safety and Health) was formed in 1979 as an independent examining board and awarding body with charitable status. We offer a comprehensive range of globally-recognised, vocationally-related qualifications designed to meet the health, safety, environmental and risk management needs of all places of work in both the private and public sectors. Courses leading to NEBOSH qualifications attract over 25,000 candidates annually and are offered by over 400 course providers in 65 countries around the world. Our qualifications are recognised by the relevant professional membership bodies including the Institution of Occupational Safety and Health (IOSH) and the International Institute of Risk and Safety Management (IIRSM). NEBOSH is an awarding body to be recognised and regulated by the UK regulatory authorities: The Office of the Qualifications and Examinations Regulator (Ofqual) in England The Department for Children, Education, Lifelong Learning and Skills (DCELLS) in Wales The Council for the Curriculum, Examinations and Assessment (CCEA) in Northern Ireland The Scottish Qualifications Authority (SQA) in Scotland NEBOSH follows the “GCSE, GCE, VCE, GNVQ and AEA Code of Practice 2007/8” published by the regulatory authorities in relation to examination setting and marking (available at the Ofqual website www.ofqual.gov.uk). While not obliged to adhere to this code, NEBOSH regards it as best practice to do so. Candidates’ scripts are marked by a team of Examiners appointed by NEBOSH on the basis of their qualifications and experience. The standard of the qualification is determined by NEBOSH, which is overseen by the NEBOSH Council comprising nominees from, amongst others, the Health and Safety Executive (HSE), the Confederation of British Industry (CBI), the Trades Union Congress (TUC) and the Institution of Occupational Safety and Health (IOSH). Representatives of course providers, from both the public and private sectors, are elected to the NEBOSH Council. This report on the Examination provides information on the performance of candidates which it is hoped will be useful to candidates and tutors in preparation for future examinations. It is intended to be constructive and informative and to promote better understanding of the syllabus content and the application of assessment criteria. © NEBOSH 2011 Any enquiries about this report publication should be addressed to: NEBOSH Dominus Way Meridian Business Park Leicester LE10 1QW Tel: 0116 263 4700 Fax: 0116 282 4000 Email: info@nebosh.org.uk

3 EXTERNAL

General comments

Many candidates are well prepared for this unit assessment and provide comprehensive and relevant answers in response to the demands of the question paper. This includes the ability to demonstrate understanding of knowledge by applying it to workplace situations. There are always some candidates, however, who appear to be unprepared for the unit assessment and who show both a lack of knowledge of the syllabus content and a lack of understanding of how key concepts should be applied to workplace situations. In order to meet the pass standard for this assessment, acquisition of knowledge and understanding across the syllabus are prerequisites. However, candidates need to demonstrate their knowledge and understanding in answering the questions set. Referral of candidates in this unit is invariably because they are unable to write a full, well-informed answer to the question asked. Some candidates find it difficult to relate their learning to the questions and as a result offer responses reliant on recalled knowledge and conjecture and fail to demonstrate any degree of understanding. Candidates should prepare themselves for this vocational examination by ensuring their understanding, not rote-learning pre-prepared answers. Common pitfalls It is recognised that many candidates are well prepared for their assessments. However, recurrent issues, as outlined below, continue to prevent some candidates reaching their full potential in the assessment.

Many candidates fail to apply the basic principles of examination technique and for some candidates this means the difference between a pass and a referral.

In some instances, candidates are failing because they do not attempt all the required

questions or are failing to provide complete answers. Candidates are advised to always attempt an answer to a compulsory question, even when the mind goes blank. Applying basic health and safety management principles can generate credit worthy points.

Some candidates fail to answer the question set and instead provide information that may be

relevant to the topic but is irrelevant to the question and cannot therefore be awarded marks.

Many candidates fail to apply the command words (also known as action verbs, eg describe, outline, etc). Command words are the instructions that guide the candidate on the depth of answer required. If, for instance, a question asks the candidate to ‘describe’ something, then few marks will be awarded to an answer that is an outline.

Some candidates fail to separate their answers into the different sub-sections of the questions.

These candidates could gain marks for the different sections if they clearly indicated which part of the question they were answering (by using the numbering from the question in their answer, for example). Structuring their answers to address the different parts of the question can also help in logically drawing out the points to be made in response.

Candidates need to plan their time effectively. Some candidates fail to make good use of their

time and give excessive detail in some answers leaving insufficient time to address all of the questions.

Candidates should also be aware that Examiners cannot award marks if handwriting is

illegible.

4 EXTERNAL

UNIT A – Managing health and safety

Question 1 A large public limited company (plc) has recently experienced a fire and

explosion resulting in multiple fatalities and extensive environmental damage.

(a) Outline a range of consequences that may affect the company

as a result of this incident. (5) (b) As a result of the incident, shareholders in the company have

raised concerns about the risk management arrangements that are in place and have called into question the Board’s annual statement that was provided as part of compliance with the Turnbull/Financial Reporting Council guidelines on ‘internal control’.

Explain the purpose of these guidelines and why they are relevant to this type of incident. (5)

An obvious consequence of the incident described in the scenario would have been the possibility of criminal prosecution by the relevant enforcing authority and the initiation of civil actions for damages. There is a possibility that regulators would subsequently have less trust in the organisation whilst licences could be lost or issued with more stringent requirements. Candidates should then have referred to the costs, both direct and indirect that would arise. Whilst certain costs would be covered by insurance, there might in future be difficulty in obtaining similar insurance provision and if this were possible, it would undoubtedly result in the payment of a much higher premium. Costs involved in cleaning up after the accident would normally not be met in an insurance claim and would fall directly to the company to finance. Further consequences which might ultimately and indirectly prove costly include the effect on the morale of the workforce with consequent difficulty in recruiting new staff; a failure to supply a promised output; the loss of confidence among shareholders and investors; and the loss of reputation amongst the companies’ clients and in its immediate community. On the whole, this part of the question attracted answers to a reasonable standard though some candidates concentrated solely on possible enforcement actions to the exclusion of the other consequences that might affect the company. In answer to part (b), candidates were expected to explain that the purpose of the Turnbull/Financial Reporting Council guidelines on ‘internal control’ is to ensure that good risk management practice is in place in order to safeguard the organisation’s assets and shareholders’ investments, to minimise losses and improve profitability and to assist in compliance with legal obligations. Their relevance to the scenario described in the question is that many of the risks they are designed to manage are realised in such an incident such as those relating typically to health, safety and the environment, business continuity, financial stability and customer relations and following the guidelines should reduce considerably the probability of such an incident occurring. There were but a few candidates who seemed to understand the guidelines that emanated from the Turnbull report and of those that did, many were unable to explain their relevance to the scenario described in the question.

Section A – all questions compulsory

5 EXTERNAL

Question 2 Explain the ‘domino’ and ‘multi-causality’ theories of accident causation, including their respective uses and possible limitations in accident investigation and prevention. (10) In explaining the “domino” theory of accident causation, candidates were expected to include Heinrich’s five step model and then to explain the development of that model by Bird and Loftus where additionally management deficiencies are addressed. The domino model may assist in the structuring of accident investigations, but, despite the additional work carried out by Bird and Loftus, it does tend to be simplistic dealing with a single chain of events that may restrict the search for multiple accident causes. Additionally it is reactive rather than proactive and is therefore not useful in predicting the likelihood of accidents whilst the Heinrich version in particular, encourages a focus on immediate rather than underlying causes. The key features of the theory of “multi-causality” include the recognition that accidents have multiple causes and that these causes combine and react with each other in a complex and random fashion. Additionally each contributory cause may have multiple causes of its own. The value of the model in accident investigation and prevention is that it encourages and emphasises the need for more in depth investigation to search for multiple underlying failures and enables the likelihood of accidents to be predicted. It also encourages the use of more systematic accident analysis techniques such as fault tree and event tree analysis. However, it tends to be a complex process, is more difficult to understand, requires more time and resources to identify the full causation picture and there are practical difficulties in reaching a decision on the extent of an investigation. In general candidates seemed to be more familiar with the ‘domino’ rather than the ‘multi-causality’ theory’. If there was a weakness in the answers provided, it was a failure on the part of some candidates to explain the uses and possible limitations of the theories in accident investigation and prevention.

Question 3 A twin-engine aircraft crashed following the partial failure of one of its engines. Although the aircraft could have landed safely on the one good engine the pilot mistakenly shut down the good engine instead of the failed engine. The aircraft was equipped with a new electronic instrument display in which the traditional analogue gauges with mechanical pointers had been replaced by less clear electronic readouts. Vibration levels for each engine were displayed on two separate gauges in the instrument cluster and investigation suggested that the pilot may have confused which of the gauges related to which engine.

Outline design features of the aircraft display system which could help to avoid similar or other errors in reading the instrumentation. (10) Design features of the aircraft display system which could help to avoid confusion resulting in errors in reading the instrumentation would initially involve separating the instrumentation for each engine and locating them on the logical side in the instrument cluster. The most important displays should be positioned more centrally and care taken to ensure that they could easily be read from the pilot position while computer displays should be designed to have the same clarity as traditional gauges.

6 EXTERNAL

Other design features would include the use of analogue gauges or electronic displays to indicate change and the use of digital gauges to show precise values; marking danger zones on analogue gauges using an appropriate colour; arranging for analogue or electronic pointers to be in a similar position for normal circumstances; providing audible or flashing warnings for safety critical conditions; minimising the number of gauges and displays and ensuring that those provided are clearly labelled; the provision of lighting for gauges and displays ensuring that the standard provided is adequate to meet different cockpit conditions and that it avoids reflection and glare from the instruments and finally and importantly ensuring the consistency of design across aircraft. There was a tendency amongst candidates not to answer the question that had been set, with some referring to the design of the cockpit and the aircraft controls rather than the instrument display system. Others discussed issues such as training and the use of flight simulators which were not display design issues. Some recognised the incident as the Kegworth air crash and dealt with wider issues relating to the incident rather than answering the question as written.

Question 4 (a) Give the meaning of the term ‘safety culture’. (2) (b) Outline a range of organisational issues that may act as barriers

to the improvement of the safety culture of an organisation. (8) For part (a), an acceptable meaning of the term ‘safety culture’ would have been the shared attitudes, perceptions, beliefs, behaviour patterns and values that members of an organisation have in the area of safety. In answering part (b), candidates were expected to outline organisational issues that could act as barriers to the improvement of the safety culture of an organisation such as, for example, the lack of management commitment resulting in a lack of trust and confidence in the management team by the employees; a failure to allocate adequate resources to support improvement; the absence of effective means of communication with employees to secure their involvement and ownership of safety issues; high staff turnover making cultural improvement difficult to embed; a history of poor employment relations; the existence of a blame culture and the lack of positive decision making by management on the level of priority accorded to safety leading to uncertainty among the workforce; the existence of a dominant pre-existing negative culture and the effects of unsupportive peer pressure and workforce cultural issues such as language barriers. There were some good answers provided for both parts of this question, though some candidates, who did not read it with sufficient care, discussed ways in which the culture might be improved rather than the barriers that might prevent its improvement. Others failed to gain maximum marks because they provided lists in answer to part (b) rather than the required outline.

7 EXTERNAL

Question 5 (a) Describe the statutory procedures for making regulations under the Health and Safety at Work etc Act 1974. (6)

(b) Outline the purpose and principles of cost-benefit analysis as it

applies to proposed regulations. (4) Part (a) of the question required candidates to be familiar with section 15 of HASAW where power to make Regulations is given to the Secretary of State with the proviso that the subject matter of the Regulations should fall within those matters contained in Schedule 3 to the Act. The procedure involves consultation by the Secretary of State with HSE (though HSE may make a proposal to the Secretary) and with relevant Government and other bodies. The proposals must lie before both Houses of Parliament for 40 days and are passed if they are not voted against in either House. If there is a vote against them, they are annulled. This is a fundamental aspect of health and safety legislation, but a number of candidates had little knowledge of the relevant statutory procedures, with some becoming confused between the procedures for making Acts and Regulations and writing at length about green and white papers and the various readings that would be necessary. A few candidates continue to refer to the HSC as opposed to the HSE. In answer to part (b), a good answer, and there were few of these, would have outline that the purpose of cost-benefit analysis is to identify the overall value to society of proposed Regulations by comparing the benefits which would arise with the costs of implementing the Regulations. In carrying out the exercise, the costs and benefits are both converted to a monetary value following established protocols for the costing of benefits in terms of the prevention of death, damage injury and ill-health. Costs are adjusted to allow for the different timescales over which costs and benefits may occur or accrue and implementation costs are estimated. Finally the calculated monetary values of costs and benefits are compared. Many candidates were unable to progress beyond a general suggestion that the costs of implementing regulations could be balanced against the benefits which would accrue to society. This was not enough to gain the four marks available.

Question 6 Your company employs 900 people at a warehousing and distribution site. Your site manager has asked for a set of summary information to be provided each month for its executive meetings in order to monitor the overall health and safety performance of the site.

Outline the possible contents of that set of information. (10)

This question required candidates to outline the contents of summary information to be provided on a monthly basis for meetings of the company executive.. Both whole site and departmental data would have been relevant. The contents might best have been outlined under the general headings of ‘reactive’ and ‘proactive’ information. Reactive information would deal with matters such as the number of lost time accidents and near miss incidents with detail provided only on those that were serious or potentially so; the current frequency or incident rates; the observed trends and patterns; the level of ill-health and sickness absence; and other relevant reactive information such as enforcement or civil actions taken and complaints received either from the workforce or from clients and the community.

8 EXTERNAL

As for the proactive measures being taken by the company, the executive would need to be given summary data on the monitoring exercises being carried out such as audits, inspections and behavioural observations; information on any relevant performance measures such as the number of risk assessments completed or reviewed; progress made in reaching site or departmental safety targets; a summary of the results of health surveillance and/or atmospheric sampling exercises and benchmarking data to enable a comparison to be made with the performance of other similar organisations. Most answers to this question were to an acceptable standard but those candidates who did not do so well had often ignored the fact that this was summary information for senior executives and suggested contents which were far too detailed for the purpose.

Question 7 A chemical reaction vessel is partially filled with a mixture of highly flammable liquids. It is possible that the vessel headspace may contain a concentration of vapour which, in the presence of sufficient oxygen, is capable of being ignited. A powder is then automatically fed into this vessel.

Adding the powder may sometimes cause an electrostatic spark to occur with enough energy to ignite any flammable vapour. There is therefore concern that there may be an ignition during addition of the powder.

To reduce the risk of ignition, an inert gas blanket system is used within the vessel headspace designed to keep oxygen below levels required to support combustion. In addition, a sensor system is used to monitor vessel oxygen levels. Either system may fail. If the inert gas blanketing system and the oxygen sensor fail simultaneously, oxygen levels can be high enough to support combustion.

Probability and frequency data for this system are given below.

Failure type/event Probability Vessel headspace contains concentration of vapour capable of being ignited

0.5

Addition of powder produces spark with enough energy to ignite vapour

0.8

Inert gas blanketing system fails 0.2 per year Oxygen system sensor fails 0.1

(a) Draw a simple fault tree AND using the above data calculate the

frequency of an ignition. (16) (b) Outline TWO plant or process modifications that you would

recommend to reduce the risk of an ignition in the vessel headspace. (4)

In answering part (a) of the question, Examiners were expecting candidates to supply a simple fault tree similar to that shown below and to calculate that the frequency of ignition would be 0.008/yr or once in every 125 years.

Section B – three from five questions to be attempted

9 EXTERNAL

While this was not a popular question, those candidates who had a good understanding of the construction of a fault tree did well though there were a few answers where gates were missing and calculations poor and incorrect whilst others contained an event rather than a fault tree.

In answering part (b), candidates could have included an outline of any relevant modifications that would reduce the risk of ignition in the vessel headspace. These could have included replacing the powder feed with a slurry in a conducting liquid; selecting and using materials with higher flashpoints to minimise the probability of a flammable atmosphere; and redesigning the inert gas blanketing system to improve reliability.

Question 8 A small company formulating a range of chemical products operates from a site on which it employs about 50 staff. Although not falling within the scope of the Control of Major Accident Hazards Regulations 1999, the site poses a risk to employees, the neighbouring community and the environment.

(a) Outline the types of emergency procedure that a site of this

nature may need to put in place in order to deal with incidents affecting the safety of site personnel. (5)

(b) Identify the factors that should be considered during the

development of a major incident procedure AND outline the arrangements that should be in place to ensure that such a procedure is effective. (15)

The intention of part (a) of the question was to require candidates to address the types of emergency the site might experience and the procedures that should be in place. These would include, for example, procedures for dealing with chemical spillage and /or release, fire evacuation and first aid treatment. Credit was also given for other credible procedures such as those required for sabotage or bomb threats.

Ignition 0.008/yr (once every 125 years)

&

Flammable vapours0.5

Spark 0.8

Oxygen > limit 0.02

&

Blanketing system fail

0.2/yr

O2 sensor system fail

0.1

10 EXTERNAL

For part (b), better answers focussed first on the development of a plan and then on the arrangements that should be in place to secure its effective implementation. Factors that would need to be considered during the development of a major incident procedure would be the level of the risk involved taking into account the nature of the chemicals, the potential rates of release, the people affected and the environmental issues involved; the existence of relevant guidance and standards and the availability of internal and external emergency resources. Arrangements that could have been identified include consultation with staff and external stakeholders such as emergency services, local authorities and utilities on the development of the plan; the provision of a control centre containing key information such as site plans, drainage plans and chemical inventories together with communication facilities; the allocation of clear responsibilities to individuals as part of the plan including arrangements for initiating the procedure and for the call-out of key staff and support services; the provision of equipment for communication between control parties in the event of an incident; the provision of emergency equipment and personal protective equipment such as that needed for spill containment, vapour suppression and fire control; consideration of the information to be given to off-site residents and neighbours and arrangements for liaison and communication with them; business continuity issues and press management arrangements; and the provision of comprehensive training for site personnel particularly those with key responsibilities with arrangements for periodic practice and review of the laid down procedures. This question was popular and generally well answered though some candidates wrote in part (a) of the arrangements that should be made rather than outlining the types of emergency procedure that should be in place whilst for part (b) others described how an incident might be dealt with rather than the arrangements for ensuring that the procedure introduced was effective.

Question 9 A manager in a manufacturing business calls out an engineer from their equipment supplier to repair and reset a piece of production equipment. After the repair there are difficulties in resetting the equipment. To help resolve this, the manager removes a fixed guard from the equipment to allow easier visibility and quicker adjustment. The engineer employed by the equipment supplier is subsequently injured on a piece of moving machinery that should have been protected by the guard.

(a) Outline possible breaches of the Health and Safety at Work etc

Act 1974. Your answer should include the company or individuals who may have committed the breaches, the specific legal requirements (including Section numbers) that have been breached AND, in EACH case, reasons for the possible breach. (16)

(b) The manufacturing business is subsequently prosecuted under

Section 3 of the Health and Safety at Work etc Act and it attempts to defend itself by blaming the acts of the manager about which it knew nothing.

Explain, with legal reasons, whether this defence could be successful. Make reference to case law where appropriate. (4)

A logical approach to answering part (a) of the question would have been to consider the various sections of the Health and Safety at Work etc Act in turn and to decide both whether they had been breached and by whom. There was, for example, a breach by the manufacturing business of their general duty to their employees under Section 2(1) in that they failed to ensure the safety of their employees by removing the guard.

11 EXTERNAL

Additionally they could be said to be in breach of Section 2 (2)(a) since they failed to provide safe plant and equipment to their employees. Similar duties lay also with the equipment suppliers whose employee was injured whilst working on unguarded machinery. The manufacturing business was also in breach of Sections 3 and 4 since, by removing a guard, they did not conduct their undertaking in such a way as to prevent non-employees from being exposed to risk and had control of premises in which they provided unsafe equipment. It could be argued that the supplier’s engineer was in breach of Section 7 since he failed to take reasonable care for his own safety by working on equipment with the guard removed whilst the manager of the manufacturing business did not comply with his duty under Section 7 or 8 by removing the guard and so interfering with something provided in the interests of safety. Consideration would also have to be given to a possible breach of Section 36 by the manager since, though the engineer worked on unguarded machinery, this was in fact as a result of the manager’s deliberate action in removing the guard. Many candidates failed to differentiate between the parties involved, often confusing the duties of the manufacturer with those of the supplier and failing to identify what was breached, by who and in what way.. In answering part (b), candidates were expected to refer to the decision in R v British Steel PLC 1995 and that in R v Nelson Group Services (Maintenance) Ltd 1998 where in the former the defence was not allowed on the grounds that it was based on the fact that its senior management was not involved while in the latter, it was allowed on the grounds that the employer had done all that was reasonably practicable. More complete answers would also have referred to Regulation 21 of the MHSWR regarding the provisions as to where the defence would not be allowed. Few candidates seemed to understand what was required in answer to this part of the question and there was little reference made to the relevant case law.

Question 10 An employee suffered a fractured skull when he fell three metres from storage racking as he was loading cartons onto a pallet held on the forks of a lift truck. A subsequent investigation found that the managers of the company were aware that it was common practice for employees to be lifted up on the forks of the vehicle and for them to climb up the outside of the racking.

(a) Outline the legal actions that might be available to the injured

person in a claim for compensation AND the tests that would have to be made for the actions to succeed. (14)

(b) Explain the meaning of ‘general’ and ‘special’ damages that may

be awarded in the event of a successful claim AND give examples of the factors that are considered in calculating their value. (6)

Part (a) of the question required candidates to outline how the torts of negligence and breach of statutory duty could apply to the given scenario. They should have outlined that, in order to succeed in an action for negligence, the claimant would need to prove that a duty of care was owed to him, that this duty was breached, that his injuries occurred as a result of the breach and that the type of injury was reasonably foreseeable. Inclusion of these stages as they applied to the scenario was required – for instance, that the employer had not done everything that could reasonably be expected to prevent a foreseeable accident in that a safe system of work had not been provided. Marks were also available for reference to relevant case law such as Wilsons & Clyde Coal v English (1938).

12 EXTERNAL

The claimant would also be able to pursue an action for a breach of statutory duty. For this claim to succeed he would need to prove that he was within the class of persons the statute was designed to protect (he was an employee acting in the course of his employment); that his injury was of the type that the requirements of the statute were intended to prevent; that a duty was placed on the defendant which he had failed to meet and that the injury sustained was a direct result of this failure. Additionally, he would have to counter any argument that the legislation involved did not allow for civil action to be taken. Candidates needed to refer to the specific statutes that had been breached and could give rise to the action namely the Work at Height Regulations, MHSWR and PUWER. Marks were available for those candidates who included references to relevant case law such as Corn v Weirs Glass (Hanley) Ltd (1960). A few candidates were unable to differentiate between negligence and breach of statutory duty whilst others made no reference to relevant case law. In answer to part (b), candidates should have explained that general damages, where no exact sum is calculable, are based on estimated financial costs, such as loss of future income in cases where there is partial or complete incapacity, sums awarded for pain and suffering and those awarded for the reduction in the claimant’s quality of life and amenity where account is taken of factors such as age, lack of mobility, degree of disfigurement, inability to pursue sports, hobbies and other interests, and diminished eligibility for social relationships. Special damages may be awarded where the exact sum is calculable such as itemised legal expenses, the loss of earnings prior to trial and the costs that have accrued in making alterations to property as a direct result of a disability resulting from the workplace accident. This part of the question was not well answered with only a few candidates able to explain the meaning of general and special damages. Some listed all possible damages which might be awarded without attempting to classify them.

Question 11 (a) Outline the meaning of ‘skill-based’, ‘rule-based’ AND ‘knowledge-based’ behaviour. (6)

(b) With reference to practical examples or actual incidents, explain

how EACH of these types of operating behaviour can give rise to human error AND, in EACH case, explain how human error can be prevented. (14)

In answering part (a) of the question, candidates should have outlined that ‘skill- based’ behaviour involves a low level, pre-programmed sequence of actions where employees carry out routine operations, often as though they were on ‘automatic pilot’. ‘Rule-based’ behaviour involves actions based on recognising patterns or situations and then selecting actions based on a learned set of rules. Finally, ‘knowledge-based’ behaviour is involved at the higher problem-solving level, when there are no set rules and a decision on the appropriate action to be taken is based on knowledge of the system. This part of the question was not well answered with few candidates able to provide an adequate meaning of the different behaviours whilst some wrote about types of error rather than behaviour.

13 EXTERNAL

For part (b), an explanation was required of how the three types of operating behaviour might give rise to human error and how such errors could be prevented. In the case of ‘skill-based’ behaviour, errors may arise if a similar routine is incorrectly selected, if there is interruption or inattention causing a stage in the operation to be omitted or repeated or if checks are not carried out to verify that the correct routine has been selected. Preventive measures would be directed at designing routines and controls so that they are distinct from each other, using feedback signals to warn when the wrong course of action is being taken, allowing adequate work breaks or job rotation to maintain attention and introducing training, competence assessment and a high level of supervision. Signals passed at danger on the railway may be a result of skill-based errors. As for ‘rule-based’ behaviour, errors may occur where, for example, the diagnosis is based only on previous experience or where sufficient training has not been given to enable employees to make an accurate diagnosis, where there is a tendency to apply the usual rule or solution even if it is inappropriate or where simply there is a failure to remember the rule that should be applied. Preventive measures include clear presentation of information, logical and easy to follow rule sets, systems designed to highlight infrequent or unusual events and the provision of training and competence assessment. Examples (if properly explained) could have included the Kegworth air crash, Piper Alpha or Three Mile Island In the case of ‘knowledge-based’ behaviour errors will occur if there is a lack of knowledge or inadequate understanding of the system, if there is insufficient time to carry out a proper diagnosis and if the problem is not properly thought through or evidence is ignored. Preventive measures would again involve training particularly in risk and hazard assessment, the provision of adequate resources in terms of information and time and the use of supervision and checking systems such as group or peer review. Flixborough and Port Ramsgate provide examples of this type of error. There were candidates who had difficulty in matching errors with the correct type of behaviour whilst others were unable to explain how human error might be prevented. Whilst examples and incidents were offered they were often connected with the wrong type of behaviour. Examiners gained the impression that some candidates had little real understanding of operating behaviour.

The National ExaminationBoard in OccupationalSafety and Health

Dominus WayMeridian Business ParkLeicester LE19 1QW

telephone +44 (0)116 2634700fax +44 (0)116 2824000email info@nebosh.org.ukwww.nebosh.org.uk