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A procedure for reviewing and improving power plant alarm systems.
patient environmental orientation, mental status and time of day. Design improvements in the following areas were suggested: door 'hold-open' devices, floor surface, equipment mobility, footwear design, nursing supervision, patient mental and physical assessment, lighting, environmental markings, and doorway and furniture design. 18.2.38 (102176) Ryden, O., Lindal, E, Uden, A., and Hansson, S.B. Differentiation of back pain patients using a pain questionnaire. Scandinavian Journal of Rehabilitan'on Medicine, 1985, 17.4, 1 5 5 - 1 6 1 . A specially designed pain questionnaire was administered to 52 consecutive out-patients referred to an orthopaedic clinic of a general hospital over a two-week period because of pain in the lower back. A clinical evaluation, based on the patients' markings on 'pain drawings', and on the degree of compatibility between their reported pain symptoms and the results of physical examinations, led to the classification of 21 cases (40%) as psychogenic. The answers of these patients to the questionnaire differed in several aspects from those of the remaining 60%. Pain was more severe, multiform and enduring, and had a more pervasive influence on their life situation; they included a higher frequency of family problems, changes of employment, stress experienced at work, sleeping problems, and 'specialist shopping'. Without being aware of which patients were classified as psychogenic cases, the orthopaedic surgeons made less auspicious prognoses for these patients and also found the questionnaire more helpful in evaluating them. When asked to rate the intensity of the patients' pain, the surgeons, unlike the patients, avoided extreme ratings. Comparing the two scales used (a six-step verbal scale and a I O-cm graphic rating scale (GRS)) for rating pain intensity, patients found the GRS
to be more meaningful. The words occupied different relative positions on the verbal scale and the GRS, and their position on the GRS fluctuated according to whether they denoted general pain or pain during attacks. The findings suggest that the questionnaire is a useful screening tool for identifying patients requiring further psychological evaluation.
18.2.39 (102185) Fink, R.T. A procedure for reviewing and improving power plant alarm systems. Vol 1. Electric Power Research Institute, Palo Alto, California, USA, Report No NP-3448, Vol 1, 1984, 284 pp. (102184: Vol 2, 1984, 142 pp.) Power plant systems have been heavily criticised in recent years. Large numbers of conditions are alarmed in the control room, often including nuisance alarms which require no operator response. In plant upsets the alarm system typically overloads the operators with information, leading them in many cases to ignore the alarm system in the initial stages of an upset. It is rare that a consistent set of rules has been applied in determining what conditions should be alarmed or in optimising the audible and visual aspects of their presentation to the operators. This report describes a procedure for review and improvement of power plant alarm systems. The procedure has been applied to review and define improvements for the alarm systems in two nuclear power plants. Although the specific examples of the review process contained in the report are for nuclear power plants, the procedure in general is applicable to fossil plants as well. The procedure.is intended for use by utilities and applies to the hardwired annunciator systems that are present in most power plant control rooms. The report includes a set of guidelines for alarm systems which are used in the review process and in the formulation of improvements.
The review includes a systematic definition of what conditions should be alarmed in the control room, an evaluation of the visual and audible aspects of alarm presentation, and a review of the systems and procedures used by the operators in interacting with the alarm system. Possible improvements to annunciator systems are described, and specific examples are given to illustrate them. Also, tests that have been performed using a dynamic alarm simulator, for the purpose of evaluating the improvements, are described in this report.
18.2.40 (102187) Goodstein, L.P. Functional alarming and information retrieval. Riso National Laboratory, Roskilde, Denmark, Report No RISOM-2511, 1985, 18 pp. This paper deals with two facets of the design and efficient utilisation by operating personnel of computer-based interfaces for monitoring and the supervisory control of complex industrial systems - e g, power stations, chemical plants, etc. These are 'alarming' and 'information retrieval', both of which are extreme ly sensitive to computerisation. F o r example, the advent of computers for display requires that some means of assuring easy and rapid access to large amounts of relevant stored information be found. In this paper, alarming and information retrieval are linked together through a multilevel functional description of the target plant.This representation serves as a framework for structuring the access to information as well as defining associated 'alarms' at the various descriptive levels. Particular attention is paid to the level where mass and energy flows and balances are relevant. It is shown that the number of alarms here is reduced considerably while information about content and interrelationships is enhanced - which at the same time eases the retrieval problem.
Applied Ergonomics
June 1987
171
to be more meaningful. The words occupied different relative positions on the verbal scale and the GRS, and their position on the GRS fluctuated according to whether they denoted general pain or pain during attacks. The findings suggest that the questionnaire is a useful screening tool for identifying patients requiring further psychological evaluation.
18.2.39 (102185) Fink, R.T. A procedure for reviewing and improving power plant alarm systems. Vol 1. Electric Power Research Institute, Palo Alto, California, USA, Report No NP-3448, Vol 1, 1984, 284 pp. (102184: Vol 2, 1984, 142 pp.) Power plant systems have been heavily criticised in recent years. Large numbers of conditions are alarmed in the control room, often including nuisance alarms which require no operator response. In plant upsets the alarm system typically overloads the operators with information, leading them in many cases to ignore the alarm system in the initial stages of an upset. It is rare that a consistent set of rules has been applied in determining what conditions should be alarmed or in optimising the audible and visual aspects of their presentation to the operators. This report describes a procedure for review and improvement of power plant alarm systems. The procedure has been applied to review and define improvements for the alarm systems in two nuclear power plants. Although the specific examples of the review process contained in the report are for nuclear power plants, the procedure in general is applicable to fossil plants as well. The procedure.is intended for use by utilities and applies to the hardwired annunciator systems that are present in most power plant control rooms. The report includes a set of guidelines for alarm systems which are used in the review process and in the formulation of improvements.
The review includes a systematic definition of what conditions should be alarmed in the control room, an evaluation of the visual and audible aspects of alarm presentation, and a review of the systems and procedures used by the operators in interacting with the alarm system. Possible improvements to annunciator systems are described, and specific examples are given to illustrate them. Also, tests that have been performed using a dynamic alarm simulator, for the purpose of evaluating the improvements, are described in this report.
18.2.40 (102187) Goodstein, L.P. Functional alarming and information retrieval. Riso National Laboratory, Roskilde, Denmark, Report No RISOM-2511, 1985, 18 pp. This paper deals with two facets of the design and efficient utilisation by operating personnel of computer-based interfaces for monitoring and the supervisory control of complex industrial systems - e g, power stations, chemical plants, etc. These are 'alarming' and 'information retrieval', both of which are extreme ly sensitive to computerisation. F o r example, the advent of computers for display requires that some means of assuring easy and rapid access to large amounts of relevant stored information be found. In this paper, alarming and information retrieval are linked together through a multilevel functional description of the target plant.This representation serves as a framework for structuring the access to information as well as defining associated 'alarms' at the various descriptive levels. Particular attention is paid to the level where mass and energy flows and balances are relevant. It is shown that the number of alarms here is reduced considerably while information about content and interrelationships is enhanced - which at the same time eases the retrieval problem.
Applied Ergonomics
June 1987
171