Ergonomic Workplace and Organisation Design in Small and Medium-sized Enterprises (SMEs)

Ergonomic Workplace and Organisation Design

in Small and Medium-sized Enterprises (SMEs)

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+49 (0) 231 9071-2071

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+49 (0) 231 9071-2070

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www.baua.de

Ergonomic Workplace and Organisation Design

in Small and Medium-sized Enterprises (SMEs)

Contents

3 Foreword

5 1 A practical example 7 2 The ERGO wheel

9 3 Internal and external partners

10 4 Method selection and determination of the need for action 13 5 Methods

19 6 Implementation of the results 21 7 The practical test

3 ER G O n O M I c WO R k p L A c E A n D OR G A n I S AT I O n DE S I G n I nSM A L L A n DME D I u M-S I z E D En T E R p R I S E S(S M ES)

The competitiveness of small and medium-sized enterprises can be increased through ergonomic workplace and organisation design just as much as the safety and health of the workers. Which methods lead to success is demonstrated in the following, taking the example of the casting cleaners’ workplaces at keulahütte krauschwitz GmbH.

With this brochure,INQA-Produktionaims to invite companies to successfully combine competitiveness with occupational safety and health. We also want to sensitise people to the fact that the “quality of work in production” develops in a dynamic process and must always be re-adjusted.

The practical description of the process is intended to make it easier to transfer the potential solutions to your company.

The project was conducted jointly by the management, experts and workers of keulahütte krauschwitz GmbH, representatives of the Berufs-genossenschaft (BG – institution for statutory accident insurance and prevention) in the mechanical engineering and metal-working industry, Berufsgenossenschaftliches Institut für Arbeitsschutz (BGIA – BG Insti-tute for Occupational Safety and Health), Dresden university of Tech-nology and Schweizerische unfallversicherungsanstalt (Suva – Swiss national Accident Insurance Organisation). Our special thanks for supporting the project goes to Mario Mackowiak, managing director of keulahütte krauschwitz GmbH.

Dr. christoph Hecker Head of InQA-produktion

c/o Berufsgenossenschaft Metall Süd

– for the Association of BGs in the Metal-working Industry

Foreword

5 ER G O n O M I cWO R k p L A c E A n D OR G A n I S AT I O n DE S I G n I n SM A L L A n DME D I u M-S I z E DEn T E R p R I S E S(SMES)

1

A practical example

Just imagine: You are the managing director of an enter-prise with about 150 employees. Your company produces small parts in a wide variety of different sizes and also reacts to orders for small quantities with great flexibility.

However, in recent weeks and months there has been an increasing number of factors which have had a direct and indirect impact on the operating result. The sickness rate has risen continuously, the quality of work has fallen and the downtimes have increased. Moreover, there has been a notification of a suspected occupational illness regarding a spinal column disorder. The origin of the un-settling events: the casting cleaning department.

keulahütte krauschwitz GmbH has successfully proved that it was able to react successfully to such problems.

INQA-Productionwould like to present the successful

solution to this problem in the following:

In order to determine the causes, an inspection of the workplaces (“on-site tour”) and the participation of the employees (e.g. foremen) are required as an initial step. The casting cleaning workplaces can obviously be charac-terised by the following features:

– Severe forward bending of the trunk is performed for various activities.

– The unit weights which have to be handled by hand (18 to 25 kg) must be classified as heavy.

– The castings are lifted at a distance from the body and

sometimes with the trunk bent forward.

– The working heights for grinding work on the bench and grinder stand cannot be adapted to suit the body size of the employees.

– The ambient conditions such as climate, lighting and noise are unsatisfactory.

– The employees do not change between the different types of work and there are no rules on breaks.

Figure 1

Typical posture when working at the grinder stand. The worker is wearing a respirator.

The fact that “strong men” work as casting cleaners is obvious but are the casting cleaners perhaps overloaded by the sum of these influences? There must be a reaction – but what?

If you examine the workplace characteristics, it quickly becomes clear that the situation is complicated and must be viewed from different aspects. Which aspects are im-portant? Scientific explanations of the factors influencing the work process often result in a system of interrelation-ships which is difficult to understand. A good, practical basis for a comprehensive analysis is offered by the so-called ERGO wheel1_{. Both the individual factors which act}

on people and the effects between the factors can be shown in a very simple way.

Figure 2

Constrained posture when removing the parts

7 ER G O n O M I cWO R k p L A c E A n D OR G A n I S AT I O n DE S I G n I n SM A L L A n DME D I u M-S I z E DEn T E R p R I S E S(SMES)

The Swiss national Accident Insurance Organization (Suva) has developed an ergonomics model in the form of a wheel1_{. people and tasks are in the centre of the wheel.}

On the one hand, the work must be adapted to suit the skills and characteristics of the people, on the other hand, people have also certain possibilities of adapting to the task. For this reason we find people again in the action circle – the ergonomics area – together with the factors workplace, work organisation, working environment and work content.

All the factors in the action circle influence the factors in the reaction circle. A strong and balanced reaction circle is a precondition for well-being at the workplace and for a good business result. The action and reaction circles are inseparably connected with each other.

The action circle is comparable with the lubricant film in a bearing. If the film tears at one point, friction and heat are produced. Without the correct lubricant being replenished, the bearing is damaged. The world of work behaves in an analogous way.

By using ergonomics, we want to lubricate the bearing and move the wheel so that it rolls forward without any major friction losses.

Just like the action circle segment “working environ-ment” shown in Fig. 4, all the other segments are also described by the individual factors which have to be

exam-ined individually and together in an assessment. The variety of individual factors and their interactions clearly show that almost all components are mutually dependent on one another. Simply changing just one individual condition may change or influence other conditions unintentionally. This may have either positive or negative effects.

2

The ERGO wheel

Figure 3

The ERGO wheel as an overall system 1 people Work content Work organization Working environ-ment people/ Task Work-place Well-being at the workplace Good business result

Action circle Reaction circle M o_t iv ati_on Occupati onal heal th c ost-e_ff ec_t iv en_e ss Occ upat ionals afety

people Work-place Work content Work organization Working environ-ment

people/

Task

people require: – a climate and light

adapted to suit the task – colour as a means of

classification, warning, feeling

– proper hygienic conditions

– a good social climate

The work equipment and the work itself produce: – heat (climate)

– air movement (climate) – humidity (climate) – dazzle – noise – vibration – radiation – hazardous substances – smell – dirt – dust

These factors have an impact both on the person causing them and on neighbouring workplaces.

Figure 4 Action circle ’work environment’ and its components 1

One example: You separate a casting cleaner’s work-place from the surrounding workwork-places to protect them against the noise level and the generation of dust. That is good for the others. But for the casting cleaner this means new conditions as regards climate, lighting and communi-cation. A completely new workplace is created which also places different demands on the worker. It may be that he does not cope with this because entirely new load situa-tions are created.

How can a solution be found? It is difficult for the

individual specialist to record all the aspects for improving the casting cleaners’ workplaces. He is generally a specialist in his own field. To solve the problem, it is necessary to have an interdisciplinary team which tackles the complex-ities of the problem. But where do you find these special-ists? Who puts the team together and who moderates it?

9 ER G O n O M I c WO R k p L A c E A n D OR G A n I S AT I O n DE S I G n I nSM A L L A n DME D I u M-S I z E D En T E R p R I S E S(S M ES)

It is recommended to include internal and external partners in the team:

– Internal partners are representatives of the manage-ment, occupational safety and health specialists, staff representatives and finally the employees affected themselves.

– External partners are important for specialised advice. For example, they may be ergonomists from the accident insurers (Berufsgenossenschaften), occupational health professionals and work hygienists, staff from health insurance funds, research institutes or engineering offices.

Moderators who have special knowledge and speak the language of the technicians and occupational health pro-fessionals have proved their worth. Accident insurance institutions and major health insurance funds are the people to contact in this case.

The moderator puts together an interdisciplinary team in consultation with the management. The management’s representative informs the working group formed in this way about the project and the current situation. This leads to a work plan with specific targets and deadlines. Smaller groups of the various partners are formed within the team in order to document the current situation as an initial step and to derive further procedure from this. In terms of

3

Internal and external partners

subject matter these groups are based on the action circle of the ERGO wheel. Individual factors are assigned to the five segments of the action circle and they have to be analysed singly and in combination. The following partners participated in our example:

– Occupational safety and health specialists – Staff representatives

– Employees

– Occupational health professionals

– Ergonomists of the accident insurance institutions – Health insurance fund

– Employees at research and development facilities

Figure 5 Members of an advisory team

The choice of the methods for the ergonomic analysis of the work system depends on the objectives and tasks of the working group. Simple or complicated methods may be used. In the case of keulahütte krauschwitz a broad range of methods were used to identify the load situa-tions. These methods were:

– Survey of the employees

– Weak point analysis in employee workshops – photo and video analyses of the workflows

– Measurement and evaluation of factors relating to the

4

Method selection and determination

of the need for action

working environment such as noise and climate – use of checklists on the load situation (standing/sitting

workplaces, posture during work), on mental components2_{or health problems}

– use of key indicator methods to evaluate lifting and carrying actions as well as for activities which involve pushing and pulling3

– Ergonomic measurement analyses (cuELA measuring system)4 people Work-place Work content Work organization Working environ-ment

people/

Task

To be taken into account: – sitting, standing

– dimensions

– room for movement

– safety distances – constrained postures – lifting, carrying – angles of view

– displays, actuators, handles

– maintenance

Figure 6

Individual factors from the “Workplace” segment 1

11 ER G O n O M I cWO R k p L A c E A n D OR G A n I S AT I O n DE S I G n I n SM A L L A n DME D I u M-S I z E DEn T E R p R I S E S(SMES)

If several analysis methods can be chosen for one segment of the work system, the assessment methods most easy to use should be selected first. They often lead quickly to a result. They provide an overview of the extent of load situations and initial indications of the nature of load in the form of a “screening procedure”. For their quantification, measuring methods are available which also provide results on the efficiency of preventive action at a later date.

The procedure for choosing the methods is to be ex-plained in the following taking the example of the “Work-place” segment with the individual factors lifting/carrying and constrained postures. Fig. 6 shows the individual factors of this workplace segment. These factors must be evaluated both individually and in combination.

The weight of the workpieces of the casting cleaners can be measured relatively easily. However, the crucial factor is also how frequently, how long and with what posture the casting cleaner holds or carries the workpiece. This results in load situations which have to be described using simple methods. In an initial stage these methods can be used by trained employees. Above all, the so-called key indicator methods are suitable for this purpose. In a second stage special assessment methods should then be applied which generally require specially trained staff. As a rule, external partners are needed for this.

13 Ergonomic Workplace and Organisation Design in Small and Medium-sized Enterprises (SMEs)

using a screening procedure, the need for action is to be initially determined in the first stage of the analysis. One recognised screening method is the “key indicator method” for lifting and carrying loads (LMM)3_{. A wide}

variety of important conditions are entered in a calcu-lation diagram which immediately provides information on the load intensities on a point rating scale. This enables you to search efficiently for suitable and effective solution variations for this one workplace. The level of possible risk is also shown using a colour identification system. You will find the diagram for our example in Fig. 7.

The use of thekey indicator methodproduced a point rating value of 36 for our casting cleaners. The load factors duration/frequency, load weight, posture and performance condition are evaluated as key indicators. When the key indicator method is used, it is necessary to have an exact knowledge of the activity to be evaluated. However, additional ergonomic know-how is not required.

At over 50 points the load situation is definitely too high and it is possible that damage to health may result (e.g. musculoskeletal disorder). point rating values of up to 25 are viewed as acceptable for people who can cope with normal load situations. A point rating value of less than 10 is generally regarded as non-critical. Our example shows there is therefore a need for action!

A more accurate determination of the workload factors

can be obtained by measurement analysis methods in step 2. Here, the range stretches from easy-to-use measure-ments, for example the lighting intensity at the workplace, down to more demanding processes for determining the noise and vibration factors. posture and body movement can also be measured with expert processes (Fig. 8 and Fig. 9).

The application of this measuring method requires extensive technical equipment and expertise on how to

5

Methods

Figure 7

Example of the colour identification of strain values in the key indicator method5 10 25 50 points Evaluation Individual resilience high low

Low load situation, health risk from physical overload is unlikely to appear.

Increased load situation, physical overload is possible for people with reduced resilience. Design measures are advisable for this group of people.

Highly increased load situation, physical over-load is also possible for people with normal resilience. Design measures are recom-mended.

High load situation, physical overload is likely to appear. Design measures are required.

use it. The evaluation of the results also requires special-ised knowledge. The external partners, e.g. the measuring services and research facilities of the Berufsgenossen-schaften, provide support.

In order to optimise the investments required and to demonstrate the success of the preventive action, measure-ments were conducted both before and after conversion of the workplace. They related, for example, to physical loads caused by the manual handling of loads or un-favourable postures. TheCUELA4_{measuring system}

(computer-assisted recording and long-term analysis of musculoskeletal loads) is suitable for this purpose.

With such an expert measurement, the exact proportion of time of the activities subjected to load situations (han-dling loads and unfavourable postures) can be quantified. Load intensities can be readily identified as the individual load phases measured can be assigned to the corre-sponding task using the measurement documentation.

To measure the physical load, sensors which measure the posture are applied to the working clothes. Moreover, Figure 8 (left)

CUELA measuring system for recording physiological loads Figure 9 (right) Noise and vibration measurements by ergonomists from the accident insurer

15 ME T H O D S Video dokumentation Memory card

Data logger

Back torsion Hip angle Knee angle Foot pressure measuring soles Angle of dorsal spine Angle of lumbar spine Figure 10

The CUELA measuring system: Principle set-up and application on test person

Figure 11

Example of an expert system for identifying multiple individual factors

pressure-sensitive measuring soles in the employee’s working shoes are used to determine the load weight. All the data of one work shift are recorded in a system worn on the body (Fig. 10).

The measurement data are evaluated and the video recording linked to an assessment program which permits the identification and documentation of the load (Fig. 11).

In the case of our company example, detailed load situations were identified with the measurements. Result: High load weights and unfavourable postures were de-tected for lifting the castings and depositing them into the wire-mesh containers and cleaning at the grinder bench.

The data for this activity were:

– Forward bending of trunk at angles of < 20°: approx. 36 %

– Load weights with weights of 20 kg: 51 %

The analysis represents the bridge to concrete improve-ments. In this way a number of preventive design actions Activity Load key indicators and proposals for prevention

Load key indicators:

Working in a position with the trunk bent forwards severely and handling high load weights when lifting and depositing the castings.

Preventive action:

– Adaptation of the working height of castings containers

– Back school for the employees: Training to lift and carry loads correctly

– Reduction of the load on individual workers through job rotation

Load key indicators:

Working in a position with the trunk bent forwards severely and handling high load weights when cleaning the castings, sometimes with the knees bent.

Preventive action:

– Adaptation of the working height of the grinding bench

– creation of larger depositing areas with adjustable height

Table 1

Prevention proposals on workplace design

17 ME T H O D S

were proposed for the following activities using the data determined (Table 1).

The prevention proposals now have to be examined in the working group to see if they can be implemented. The advisory teams put forward a number of proposals for the different segments of the ERGO wheel. Therefore, the practitioner has the final word on the practicability of the proposal.

19 ER G O n O M I c WO R k p L A c E A n D OR G A n I S AT I O n DE S I G n I nSM A L L A n DME D I u M-S I z E D En T E R p R I S E S(S M ES)

In the example of our casting cleaner, the following measures were proposed to improve the work situation: – Elimination of constrained postures when removing the

parts from the wire-mesh container pallets and depos-iting the parts in them

– Adaptation of the working heights to the highly different employees

– Reduction in the holding work during grinding.

In addition to the above measures from the segment “Work-place design", the following proposals were also made: – Elimination of one-sided workflows, optimisation of the

break system

– Optimisation of the lighting and extraction features.

You should always discuss the preventive action with the employees and select the best options together. Workshop results documented on flip charts and posters provide assistance. You will find that in most cases those directly affected arrive at the same solution variations as the team of experts.

The objective is then to find the best technical solution for the working conditions. To this end it has proved worthwhile to request several manufacturers of work equipment to have their products tried out in practice. In this way, the employees on the shop floor can test which

6

Implementation of the results

Figure 12/13

Examples of flip charts from workshops with the employees lifting tool, which balancer or lifting table is suitable under

practical conditions.

The implementation of organisational changes which are to be made directly in your company is agreed on between the management and the working group and incorporated in the work plan.

All solutions, whether the acquisition of lifting tools or new break regulations, are discussed jointly and appro-priate decisions taken, stipulating deadlines and areas of responsibility.

Figure 15

21 ERGOnOMIcWORkpLAcE AnDORGAnISATIOnDESIGn InSMALL AnDMEDIuM-SIzEDEnTERpRISES(SMES)

In our example the solutions are as follows: – use of lifting/tilting tables

– use of wire-mesh containers with better access – Larger depositing areas on the grinding bench – Adaptation of the heights of work tables and grinding

benches

– Introduction of short-break systems – cycle changes

– Job rotation

– Renewal of the extraction and lighting facilities

The important aspect is that you give the employees enough time to be able to adapt to the changes in the working conditions. The working group should continue to provide support. After the introductory phase had been completed, follow-up evaluations of the loads and sub-sequent measurements of other physical or mental factors can take place. As a result, you also obtain operational data on the cost/benefit situation.

7

The practical test

Figure 16 Use of a lifting/ tilting table

For the “Workplace design” segment the following improvements were verified for the load factors:

The load situations caused by trunk positions with bending greater than 20° (Fig. 18, yellow columns in the left-hand diagram) were almost completely eliminated.

Apart from the harmful bent trunk positions, the pro-portionately high number of load handling operations (Fig. 19, orange and red columns in the left-hand diagram) were also reduced by the design measures taken. After a period of about one year, the working group should meet again and analyse how the situation has developed. An Figure 17

Example of the extension of work through job rotation 1

control workplace Quality feedback

Jobrotation

answer should be found to the following questions: – Has the sickness rate fallen?

– Have the quality of work and the employees’ motivation improved?

– Has there finally been a positive impact on the business result?

If, as a result, the business result and the well-being of the employees have improved, your accountants will also be delighted!

The example shows that only an interdisciplinary team of experts in close collaboration with the company’s workers can overcome such complex tasks. Methods and processes which are also suitable for small and medium-sized enterprises are available and have proved their practicability. If you want to solve similar problems, you will also find experienced partners in your area. And the ERGO wheel can be of valuable assistance to you.

23 †HE pRAcTIcAL TEST

Trunk inclined forwards [°] (angle classes)

before

Frequency [%] 60 30 0 3,2 =‹-2 -2‹›20 20‹›40 40‹›60 60‹›90 90›= 60,3 32,5 3,3 _0,7 0,0 Angle range [°]

Trunk inclined forwards [°] (angle classes)

after

Frequency [%] 93 46 0 6,8 =‹-2 -2‹›20 20‹›40 40‹›60 60‹›90 90›= 92,9 0,3 _{0,0 0,0 0,0} Angle range [°] Figure 18

Bent trunk positions before and after ergonomic intervention 34 14 0 28,3

Load weight [kg] (load weight classes)

before

Frequency [%]

0 0‹›5 5‹›10 10‹›15 15‹›20 20‹›25 25‹›30 30‹›35 35‹›40 40›= 0 0‹›5 5‹›10 10‹›15 15‹›20 20‹›25 25‹›30 30‹›35 35‹›40 40›= Load weight [kg]

Load weight [kg] (load weight classes)

after

Frequency [%] 73 36 0 Load weight [kg] 33,5 28,3 0,2 6,6 2,6 1,0 72,6 0,3 0,1 0,1 10,2 15,8

0,0 0,0 0,0 0,0 Figure 19_{Load handling before}

and after ergonomic intervention

Literature

1 Ergonomie. Erfolgsfaktor für jedes unternehmen, Suva, Luzern, 1996, Schmitter, D; et alia

2 Rechnergestütztes Dialogverfahren für die Bewertung und Gestaltung von Arbeitstätigkeiten REBA 7.1, Dresden university of Technology, InfoMediaVerlag e.k., 2005, Richter, p; et alia

3 Leitmerkmalmethoden Heben und Tragen/ziehen und Schieben, BAuA, Berlin, Juli 2007, Steinberg, u.; et alia 4 Einsatz des Messsystems cuELA zur Erfassung und

Bewertung physischer Arbeitsbelastungen, BGIA, Sankt Augustin, 2006, Ellegast, R.p.; Hermanns, I.

http://www.hvbg.de/d/bia/fac/ergonomie/pdf/cuela.pdf

Abbreviations

BAuA Bundesanstalt für Arbeitsschutz und

Arbeitsmedizin [Federal Institute for Occupational Safety and Health], Berlin

BG Institution(s) for statutory accident

insurance and prevention

BGIA Berufsgenossenschaftliches Institut für

Arbeitsschutz [BG Institute for Occu-pational Safety and Health], Sankt Augustin

CUELA computer-assisted recording and long-term analysis of musculoskeletal loading

LMM key indicator method, BAuA, Berlin

MMBG BG in the mechanical engineering and

metal-working industry, Düsseldorf

REBA 7.1 computer-assisted dialogue process for the evaluation and design of work activities allowing for occupational safety and health, InfoMediaVerlag e.k., Bochum, 2005

Suva Schweizerische

unfallversicherungs-anstalt [Swiss national Accident Insur-ance Organization], Lucerne

Imprint

Ergonomic Workplace and Organisation Design in Small and Medium-sized Enterprises (SMEs) Authors:

Dr. Rolf Ellegast, Markus post, Berufsgenossenschaftliches Institut für Arbeitsschutz, division 4, work science/ergonomics group, Sankt Augustin

Dieter Schmitter, Suva, Lucerne, pDF team Healthy companies, ergonomics division

Detlef Trippler, Berufsgenossenschaft in the mechanical engineering and metal-working industry, prevention department, ergonomics group, Düsseldorf

Thematischer Initiativkreis – Arbeitssysteme in der produktion – InQA-produktion der Initiative neue Qualität der Arbeit (InQA)

[Theme action group – Work Systems in production –

InQA production of the new Quality of Work Initiative (InQA)] c/o Bundesanstalt für Arbeitsschutz und Arbeitsmedizin, Berlin nöldnerstraße 40–42 10317 Berlin

Telephone +49(0)30 515 48-44 33 Fax +49(0)30 515 48-4170 schust.marianne@baua.bund.de www.inqa-produktion.de publisher:

Bundesanstalt für Arbeitsschutz und Arbeitsmedizin [Federal Institute for Occupational Safety and Health] Friedrich-Henkel-Weg 1–25 D-44149 Dortmund

Telefon +49.2 31.90 71-0 Fax +49.2 31.90 71-24 54 poststelle@baua.bund.de www.baua.de Editor: pascal Frai, BAuA

Design: GuD – Helmut Schmidt, Braunschweig

Responsible for Translation: Verena Frfr. v.d. Heyden-Rynsch, Dortmund heyden.rynsch@t-online.de

photos: uwe Völkner – FOX-Fotoagentur, Lindlar/cologne photo p. 15: Dr. Rolf Ellegast, BGIA, Sankt Augustin photo p. 9, 14, 19: Detlef Trippler MMBG, Düsseldorf

production and printing: Rademann GmbH Druck und Medienhaus, Lüdinghausen Reproduction, also of extracts, only with the prior approval of the BAuA.

1st_edition

Dortmund/Berlin 2007 978-3-88261-578-4

inqa@baua.bund.de www.inqa.de