1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS 3375 : Part 5 : 1997 I
2、CS 03.100.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Management services Part 5. Guide to determination of exposure limits, recovery times and relaxation times in work measurementBS 3375 : Part 5 : 1997 This British Standard, having been prepared under the direction of
3、 the Management Systems Sector Board, was published under the authority of the Standards Board and comes into effect on 15 September 1997 BSI 1997 The following BSI references relate to the work on this standard: Committee reference MS/1 Draft for comment 93/409005 DC ISBN 0 580 26825 X Amendments i
4、ssued since publication Amd. No. Date Text affected Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee MS/1, Work study and organization and methods, upon which the following bodies were represented: Civil Service College Er
5、gonomics Society Federation of the Electronics Industry GAMBICA (BEAMA Ltd.) HM Treasury Institute of Administrative Management Institute of Management Services Institute of Quality Assurance Loughborough University of Technology Methods Time Measurement Association Ltd. Trades Union Congress Coopte
6、d memberBS 3375 : Part 5 : 1997 BSI 1997 i Contents Page Committees responsible Inside front cover Foreword ii Introduction 1 Guide 1 Scope 1 2 References 1 3 Definitions 1 4 General 2 5 Determination of relaxation and recovery times and exposure limits 2 Annexes A (informative) Derivation of the ta
7、bles for relaxation factors 15 B (informative) Derivation of regimes for recovery and exposure times 19 C (normative) Benchmark activities for assessing work intensities 22 Tables 1 Posture RF % 3 2 Adjustment factors for posture RF % 3 3 Walking RF % 3 4 Increments to walking RF % for load carrying
8、 5 5 Work intensity RF % 5 6 Simplified RF % table 6 7 Vigilance activity 8 8 Threshold WGBT values (T thr )1 2 9 Work periods in cold environments 13 A.1 Energy rates for various postures 15 A.2 Energy rates for walking on the level, unladen 15 A.3 Energy rates for various activities 1) 15 A.4 RA %
9、 values as a function of metabolic rate 16 A.5 Energy rates for loads carried on the level at 4 km/h 16 A.6 Conversion of load carrying wattage to RF % contribution 17 A.7 Recovery period factor (F) for various hold intensities 17 A.8 Summary of bases for the RF tables 18 B.1 Fractional body areas 2
10、0 B.2 Required equivalent clothing thickness (ECT) 21 B.3 Weightings for items of clothing 21 B.4 Summary of derivation of regimes for recovery and exposure times 21 C.1 Benchmark activities 22 Figures 1 Flow chart to determine RF % and recovery requirements 4 A.1 Maximum hold time 18 List of refere
11、nces 24ii BSI 1997 BS 3375 : Part 5 : 1997 Foreword This Part of BS 3375 has been prepared by Technical Committee MS/1. It supersedes DD 204 : 1991, which is withdrawn. This Part of BS 3375 provides guidance and recommendations. It should not be quoted as if it were a specification and particular ca
12、re should be taken to ensure that claims of compliance are not misleading. BS 3375 is a series of standards published in response to a demand for information and guidance on how the various terms contained in BS 3138 : 1992 Glossary of terms used in management services interrelate. This Part relates
13、 specifically to the application of the results of work measurement; it should not be used outside this context. In recent years there has been considerable development of the techniques and broadening of the areas of application of work study and organization and methods. This sphere of activity an
14、d practice of techniques is known as management services. The publication of this Part of BS 3375 reflects the fact that management services methodologies are now used across the entire spectrum of commercial, industrial, governmental and voluntary activities and are applied to all types of work and
15、 work situation. BS 3375 comprises the following Parts: Part 1. Guide to organization study Part 2. Guide to method study Part 3. Guide to work measurement Part 4. Guide to work performance control Part 5. Guide to determination of exposure limits, recovery times and relaxation times in work measure
16、ment When using this Part of BS 3375, it is also important to refer to the terms listed in BS 3138 : 1992 Glossary of terms used in management services. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cove
17、r, an inside front cover, pages i and ii, pages 1 to 24, an inside back cover and a back cover. BSI 1997 1 BS 3375 : Part 5 : 1997 Specification Introduction In this Part of BS 3375, the background to relaxation times and recovery periods is reviewed and the method is given for using work measuremen
18、t data to determine the amount of relaxation time (RT) appropriate to the task and the recovery period (RP) suitable for the conditions or environment surrounding the task. The abbreviation RF (for relaxation factor) is used throughout, in place of the older term RA (for relaxation allowance) with i
19、ts connotation of an arbitrarily awarded allowance. Where RA is mentioned, it is to refer to past applications and interpretations. Annex A describes the basis of the RF tables which are given in this Part of BS 3375. Annex B describes the basis of the various regimes for exposure times and environm
20、ental conditions. Annex C gives benchmark examples for use in assessing work intensity. 1 Scope This Part of BS 3375 gives guidance on determining relaxation times and recovery periods for human activities that have been measured by any of the work measurement techniques identified in BS 3138 and di
21、scussed in BS 3375 : Part 3. The guidance given in this Part of BS 3375 should be of particular value to those training in the field of management services. 2 References 2.1 Normative references This Part of BS 3375 incorporates, by dated or undated reference, provisions from other publications. The
22、se normative references are made at the appropriate places in the text and the cited publications are listed on page 24. For dated references, only the edition cited applies; any subsequent amendments to or revisions of the cited publication apply to this Part of BS 3375 only when incorporated in th
23、e reference by amendment or revision. For undated references, the latest edition of the cited publication applies, together with any amendments. 2.2 Informative references This Part of BS 3375 refers to other publications, that provide information or guidance. Editions of these publications current
24、at the time of issue of this Part of BS 3375 are listed on page 24, but reference should be made to the latest editions. 3 Definitions For the purposes of this Part of BS 3375 the definitions given in BS 3138 : 1992 and BS 7802 : 1995 apply, together with the following. 3.1 physical work Activity in
25、 which parts of the body are used to change or move something (including the body itself). There is an expenditure of energy by the body which is measurable physiologically. 3.2 non-physical work Activity in which the person carries out few or limited movements with parts of the body, which do not o
26、f themselves impose a physical load on the body. The principal purpose of the activity is the mental processing of information, with inputs by the senses and outputs by speech, or communication to a device through some means such as a keyboard, steering wheel, or an appropriate control mechanism. Su
27、ch work can impose a mental load. 3.3 personal needs The group of activities that are personal to an individual, which need to be undertaken from time to time to attend to personal hygiene, etc. 3.4 closure point A point at which the work reaches a natural termination, either intermediate or final.
28、It can be defined by the task itself, or set individually by the operator, e.g. the end of a batch of data being entered or the end of a stage of thinking something through. 3.5 relaxation factor (RF) A factor, normally expressed as a percentage, which depends on the nature of the work done during t
29、he basic time and which is applied to the basic time in order to derive the relaxation time for that activity. 3.6 relaxation time (RT) An addition to the basic time: a) to afford relief from the physical and mental efforts of carrying out the work under specified conditions at standard performance;
30、 b) to allow attention to personal needs. NOTE. The additional time will depend upon the nature of the work and may be spent away from the workplace under management direction. Relief from fatigue may also take place during unoccupied time or recovery periods, so long as the duration of these period
31、s is appropriate for relaxation. 3.7 recovery period (RP) A withdrawal period to relieve stress caused by the work environment where adequate protection is impracticable. It should start when established threshold limits for the work are reached and should be spent away from the workplace. Recovery
32、periods can be concurrent with relaxation time and unoccupied time, and other tasks can be undertaken during the withdrawal periods.2 BSI 1997 BS 3375 : Part 5 : 1997 1) C. Barth was a mathematician who worked with Merrick (see ref. 2) and Taylor (see ref. 12) to analyse a great number of time recor
33、dings of people at work, collected by Merrick and Taylor and their employees. Cited in Cohen (see ref. 2). D. V. Merrick was one of Taylors (see ref. 12) associates who carried out work as part of Taylors consultancy practice. F. W. Taylor was an American mechanical engineer, born in 1856, died in P
34、hiladelphia in 1915. He addressed himself to the question What should constitute a days work? He built up a substantial management consultancy practice and laid much of the foundation of modern time study and management practice. 3.8 blanket RF A value assigned for RF when it is inappropriate for an
35、y reason to apply the detailed procedures given in this Part of BS 3375. 3.9 CLO A unit of insulation related to clothing. It is the insulation required to keep a seated person comfortable at an air temperature of 21 C in an air movement of 1.0 m/s. NOTE. This amounts to an ordinary suit, shirt, und
36、erwear, etc. One CLO is equivalent to 0.18 K m 2 (kcal/h) of body surface. 3.10 tog A unit of thermal resistance widely used in the field of textiles and clothing. NOTE. One tog is equivalent to 0.1 m 2 K/W. 4 General 4.1 Background There are a very large number of RA tables in existence. An effect
37、of the diversity of tables is that there can be very wide differences between observers in deriving RA for a given task. Most RA tables are based on the Bedaux concept of adding a percentage to the basic time for an element to allow for relaxation and recovery. None of the published tables have been
38、 accepted officially, either nationally or internationally, although specific industry groupings may have accepted a particular table for internal use. The International Labour Office (ILO) book on work study 1 gives tables specifically as examples; this does not constitute acceptance or authorizati
39、on in any way. Attempts have been made to find alternative ways of determining the addition to the basic time, including the following: a) Barth and Merrick had an empirical approach, which led to a family of curves linking element duration and percentage allowance 2 1) ; b) Kerkhoven linked the sta
40、ndard time to the minimum possible time for the work 3, 4; c) REFA and others used energy levels 5; d) ILO established various kinds of points assessment systems (1). Most of these are not widely used in ordinary work study practice in the UK. The basis for this Part of BS 3375 is the research devel
41、oped by Spitzer and Hettinger in Germany 6 and is supported by BS EN 28996. 4.2 Constraints on the applicability of this Part of BS 3375 The relaxation factor (RF) derived from the recommendations in this Part of BS 3375 can be inappropriate for very heavy work. Standard times should not be set for
42、work practices that are unsafe, or where circumstances in any way contravene the Health and Safety at Work etc. Act 1974 or related legislation (see 7, 8, 9, 10, 11). If such circumstances exist, then it is wrong to modify RF % or RT values to compensate. If use of this Part of BS 3375 leads to a sm
43、aller standard time than that already existing for work in substandard conditions, then this suggests that the conditions need to be improved before the new standard time can be applied. 5 Determination of relaxation and recovery times and exposure limits 5.1 Method of determination It is always ass
44、umed, when applying a standard time, that the operator is a qualified worker (see BS 3138), with the necessary physical attributes and the required intelligence and education, skill and knowledge to carry out the work in hand to satisfactory standards of safety and quality. If this is not wholly tru
45、e, then the standard time as derived by use of this Part of BS 3375 may be inappropriate. When determining relaxation times and recovery periods, no distinction can be made between male and female persons. A person of either sex, with the necessary attributes, can be a qualified worker for the task
46、under consideration. Furthermore, the Equal Pay legislation requires that male and female workers receive the same pay for work that is broadly similar; to have different RF % for the same work for male and female persons would be contrary to this legislation. The calculation of relaxation time and
47、recovery period takes place after the work has been measured by a suitable work measurement technique. This will have produced a basic time (see BS 3138) for the work, element by element; with the coarser measurement techniques, the time may be for the work cycle as a whole. The result obtained by f
48、ollowing the procedure described in clause 5, is a RF % to be added to the basic time with, where appropriate, guidance as to suitable work regimes for dealing with special types of work or environmental conditions. BSI 1997 3 BS 3375 : Part 5 : 1997 Figure 1 gives a flowchart which shows the sequen
49、ce of steps to be taken. Begin at the point marked START and follow the procedure through the various decision branches to the end. The chart contains a number of conditional jumps which are observed at the appropriate time. The procedure for dealing with physical work is described in 5.2, while 5.3 describes how to deal with non-physical work and 5.4 describes how to deal with the environment. The application of the results is described in 5.5, with guidance about the local use of the values obtained from following the flowchart (see fi
