ErgoVSM: A Tool for Integrating Value Stream Mapping and ... · ErgoVSM: A Tool for Integrating Value Stream Mapping and Ergonomics in Manufacturing Caroline Jarebrant,1,2 Jorgen

ErgoVSM: A Tool for Integrating Value Stream Mappingand Ergonomics in ManufacturingCaroline Jarebrant,1,2 Jorgen Winkel,2,3 Jan Johansson Hanse,4 Svend Erik Mathiassen,5

and Birgitta Ojmertz1

1 Swerea IVF, Molndal, Sweden2 Department of Sociology and Work Science, University of Gothenburg, Gothenburg, Sweden3 Department of Management Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark4 Department of Psychology, University of Gothenburg, Gothenburg, Sweden5 Centre for Musculoskeletal Research, Department of Occupational and Public Health Sciences, University of Gavle, Gavle,Sweden

Abstract

Value stream mapping (VSM) is a lean tool aiming at waste reduction. Previous research suggeststhat the use of VSM may result in work intensification and thus an increased risk for the workers ofdeveloping work-related musculoskeletal disorders (MSD). In the current study, VSM was developed toalso consider physical exposure in the analyzed production system (ErgoVSM). As the VSM, ErgoVSMis based on a participatory approach. ErgoVSM was tested in a Swedish manufacturing company. Theresults suggest that ErgoVSM catalyzes change processes to include intervention proposals emphasizingergonomics in addition to waste reduction. Thus, ErgoVSM appeared useful for the investigated targetgroup of production engineers and experienced operators. The performance improvements suggestedwhen using the ordinary VSM seemed not to be hampered by adding the ergonomics complement.However, the use of ErgoVSM was somewhat more time consuming than the use of VSM. In conclusion,ErgoVSM is suggested as a feasible tool to be used by production engineers and experienced operatorsfor including ergonomics considerations in the rationalization process. C© 2015 Wiley Periodicals, Inc.

Keywords: Rationalization; Lean production; Musculoskeletal disorders; Participatory ergonomics;Organizational sustainability

1. INTRODUCTIONMusculoskeletal disorders (MSD) continue to be aprominent health problem in working life despitedecades of ergonomics intervention research and cor-responding initiatives in practice (e.g., Driessen et al.,2010; Rivilis et al., 2008; van Oostrom et al., 2009).The manufacturing industry in particular has sufferedfrom MSD (e.g., Swedish Work Environment Author-ity, 2012). A recent review by Westgaard and Winkel

Correspondence to: Jorgen Winkel, University of Gothenburg,Department of Sociology and Work Science, Box 720,SE-40530 Gothenburg, Sweden. E-mail: [email protected]

View this article online at wileyonlinelibrary.com/journal/hfm

DOI: 10.1002/hfm.20622

(2011) provided an empirical basis to state that ra-tionalizations may, in their own right, cause MSDand mental health problems, thus weakening or elim-inating the benefit of “classical” ergonomics interven-tions. Most ergonomics interventions are realized at thelevel of individual operators in an attempt to changephysical and/or psychosocial working conditions forthe individual (Westgaard and Winkel, 2011; Wijk &Mathiassen, 2011). In contrast, rationalization priori-tizes creation of value at a system level by minimizingnon-value-adding activities (non-VAA, or waste; forreferences, see Westgaard & Winkel, 2011) and doesnot as such consider the possible impact on the riskfor individual workers of contracting MSD. Thus, er-gonomists, working within a health paradigm, andproduction engineers, devoted to improving system

Human Factors and Ergonomics in Manufacturing & Service Industries 00 (00) 1–14 (2015) c© 2015 Wiley Periodicals, Inc. 1

A Tool for Integrating Value Stream Mapping Jarebrant, Winkel, Johansson Hanse, et al.

performance, may have conflicting objectives (Wells,Mathiassen, Medbo, & Winkel, 2007).

Today, rationalization work is often based on leanproduction, emanated from Toyota’s production phi-losophy. The companies have their own descriptions oftheir guiding principles for their production systems,commonly visualized by a “lean-house” and where dif-ferent specific tools and methods are used for improve-ment work. This is described in, for example, Liker(2004) as Toyota’s 14 management principles. A valuestream includes all VAA as well as non-VAA, in a spe-cific value stream refining products (Rother & Shook,2009). A VAA performed by an operator is named valueadding work (VAW). VAW is defined as that part of theoverall processing time that is spent by operators in ac-tions creating value as perceived by the customer (Liker,2004). A plant generally contains several value streams.A common tool for analyzing and improving a pro-duction process within this framework is value streammapping (VSM), originally introduced by Rother andShook in 2000 (Rother & Shook, 2009).

Recent studies of manual work in industry, forestry,and dentistry indicate that non-VAW may be associ-ated with lower task exposures than VAW (Forsman,Neumann, Palmerud, & Winkel, submitted March2014; Kazmierczak, Mathiassen, Forsman, & Winkel,2005; Jonker et al., 2011; Jonker et al., 2013;Ostensvik et al., 2008; Palmerud, Forsman, Neumann,& Winkel, 2012). Reduction of non-VAW by ratio-nalization may therefore increase the risk for devel-opment of MSD partly because non-VAW is asso-ciated with lower task exposures, and partly due toreduction in the overall exposure variation in the job(Mathiassen, 2006). Increasing the proportion of VAWin the production process is an explicit aim in leanproduction and the target purpose of using VSM. Thismay thus reduce the “porosity” of the working dayand, in turn, cause a “work intensification” (Burchell,Ladipo, & Wilkinson, 2002; Eurofound, 2012; Green,2004; Westgaard & Winkel, 2011), that is, an increasedoverall physical work load and a decreased physicalvariation, both of which may increase risk for develop-ing MSD. However, integrating the needs for effectiveproduction and a healthy workforce in the analysis anddevelopment of production systems may be a solutionto the apparent conflict of interest between ergonomicsand rationalization (Westgaard & Winkel, 2011). Thisemphasis on the role of ergonomics as an inte-grated discipline in the development of effective andsustainable production is well in line with the

current, recently adopted, policy of the InternationalErgonomics Association (Dul et al., 2012).

With this background, the present study aimed todevelop a method for integrating ergonomics in anexisting VSM tool and to examine its applicability ina target group of industrial operators. The long-termpurpose of integrating ergonomics in VSM is to allowsimultaneous consideration of production system per-formance and physical risk factors for development ofMSD in the manufacturing industry.

2. VALUE STREAM MAPPING(VSM)VSM as used in the present study is limited to the prod-uct’s production path in a specific factory as describedin Rother and Shook (2009). VSM is a participativepaper-and-pen tool aiming to identify and minimizenon-VAA, thus decreasing lead time by increasing theproportion of time spent at VAA (Figure 1A and B).VSM is typically performed by a group of operators andproduction engineers (preferably n � 5–8) represent-ing different functions in the value stream. The analystsliterally illustrate the value stream of products and in-formation, for instance on plastic films (Figure 1B).

“Lead time,” according to the definition used byRother and Shook (2009), is the time spent by onepiece in a process or value stream, all the way fromstart to finish. The time spent at VAA is often mea-sured as the proportion (percentage) of the lead timeduring which value is added to the product. During thenon-VAA, the product parts reside in “non-necessaryactivities,” for instance, when products are in stock,including buffer zones. In VSM, the amount of mate-rials in the flow is converted to a figure equivalent tothe number of production days it will last to supplythe customer. The amount of materials includes bothraw materials, product parts, and completed productsin the flow, whether in process or in stock. Stocks maybe reduced, for example, by improving the interprocessbalancing in the value stream or by improving planningand control systems and changing purchasing routines.According to Rother and Shook (2009), the VSM toolalso assesses, 1) Cycle Time (CT), the time that elapsesbetween one part coming off the process to the nextpart coming off; 2) “change-over time,” the time ittakes to switch from producing one product to anothervariant or product; and 3) number of operators work-ing in the value stream. Thus, in VSM, humans are only

2 Human Factors and Ergonomics in Manufacturing & Service Industries DOI: 10.1002/hfm

Jarebrant, Winkel, Johansson Hanse, et al. A Tool for Integrating Value Stream Mapping

Figure 1 A group of operators and a production engineer performing value stream mapping (A). A value stream as it mayappear when visualized on a plastic film, including sticky notes, indicating processes and tasks (B). Ergonomics assessmentsentered on the plastic film by one of the operators (C).

considered in general terms and only in terms of thenumber of operators needed at each process step and intotal during a shift. VSM does not, per se, include anyconsiderations to the working conditions of operatorsin the system.

On the basis of a VSM of current production (a “cur-rent state map”), a list of proposals of how to reducewaste is produced. Feasible ideas are then included ina “future state map” in which non-VAAs have beenminimized according to the lean production strategy(Rother & Shook, 2009). Finally, an action plan is es-tablished based on the future state map.

3. THE ErgoVSM TOOL—EVIDENCEBASETo include considerations to ergonomics consequencesof rationalization as supported by VSM, we developedan ergonomics add-in module to be used as an in-tegrated part of the VSM process. The primary basis

of the module is current scientific evidence on occupa-tional risk factors for MSD. In general, the internationalscientific community agrees that the risk of low backdisorders increases with “heavy” physical load, such asin manual handling of heavy objects, frequent bend-ing, and twisting (da Costa & Vieira, 2010; Griffithset al., 2012; Hoogendoorn et al., 1999). For MSDs in theupper extremities and shoulder/neck, important work-related risk factors include repetitive actions, large forcedemands, and vibration (Ariens et al., 2000; Cote et al.,2008; Palmer & Smedley, 2007; van der Windt et al.,2000; van Rijn, Huisstede, Koes, & Burdorf, 2010). Theimpact of these factors on health and performance de-pends in turn on the exposure level, frequency, andduration (cf. Winkel & Mathiassen, 1994; Winkel &Westgaard, 1992, 1996).

As mentioned above, “work intensification” is sug-gested in the literature to be a likely result ofrationalization (Burchell et al., 2002; Docherty, Forslin,Shani, & Kira, 2002; Green, 2004) with a possible effect

Human Factors and Ergonomics in Manufacturing & Service Industries DOI: 10.1002/hfm 3


on MSD prevalence (cf. Westgaard & Winkel, 2011).Intensified work may be expressed in terms of reduced“exposure porosity”, that is, a reduced occurrence ofshort periods allowing recovery during the workingday (Jonker et al., 2011, 2013; Ostensvik et al., 2008;Palmerud et al., 2012).

Lack of physical variation is commonly believed tobe a risk factor for MSD (Mathiassen, 2006). Thus, pro-longed, uninterrupted periods of, for example, sittingor light repetitive work may represent a risk for devel-opment of MSD (National Research Council, 2001).Prolonged heavy dynamic work may also imply anincreased risk for developing MSD, albeit throughother biological mechanisms. However, an appropri-ate temporal alternation of these two types of physi-cal exposure may increase variation and thus reducerisk.

4. DESCRIPTION OF THE ErgoVSMTOOL4.1. Basic Goals and DevelopmentProcess

As a foundation for the development of the new er-gonomics module to VSM, we decided that it shouldas far as possible fulfill the following criteria:

� Be embedded in the existing VSM tool to facil-itate adoption among ordinary users of VSM(identified as also being the prime users ofErgoVSM)

� Be participative in the same way as the VSMtool

� Be evidence based� Stimulate conception of ideas in the user

group emphasizing simultaneous considerationto waste reduction and ergonomics

� Require modest education

On the basis of these goals, the ErgoVSM tool wasdeveloped over a period of 2 years in an iterative processbetween the present authors and intended users at threeSwedish manufacturing companies.

4.2. Terminology

ErgoVSM assesses physical exposure structured by“tasks,” “value streams,” and “jobs.” “Task” is definedas a separate, meaningful part of a production that oneindividual may be charged to execute. Consequently,

“task exposure” is the physical exposure of an opera-tor when performing the task. “Value stream” is de-fined as a “sequence of activities required to design,produce, and provide a specific goods or service, andalong which information, materials, and worth flows”(Business Dictionary, 2013). “Job” refers in the presentcontext to the composition of tasks that one specificoperator is assigned to carry out within a given valuestream. Thus, a full job may include tasks also fromother value streams.

4.3. Structure

The ErgoVSM tool is, as traditional VSM, based onvisualization and dialogue to support the process frommapping a current state to creating a future state of avalue stream, including a list of actions needed to reachthis (Figure 2).

A value stream is chosen for analysis. The VSMprocedure is followed, and VSM data are visualizedas described in Section 2. This analysis is followedby ergonomics assessments (Figure 1C). In ErgoVSM,these assessments consider the risk factors for MSD de-scribed in Section 3 in four major categories: postures,forces, physical variation, and porosity (for details, seeSection 4.4). The procedure is carried out for the cur-rent state as a basis for the dialogue on waste reductionand ergonomics considerations.

Proposals for improvements in the value stream arelisted, just as in ordinary VSM, but in addition tothe consequences in terms of product and informa-tion streams, ergonomics is considered as a basis fordrawing the map of the so-far virtual future state. Ad-justments are made in an iterative discussion process.Finally, an action plan of interventions is established,including allocation of responsibilities for the differentinterventions and a time schedule.

The complete ErgoVSM process comprises the fol-lowing information (Figure 2):

Current state:

� Manual working time (i.e., Duration of VAW +Non-VAW) at each task and for one product (orfor a defined batch)

� Physical exposure associated with each task inthe production

� Physical exposure associated with the total valuestream and all jobs, estimated from the durationand exposures of the constituent tasks



Figure 2 An illustration of the different steps included in the ErgoVSM from the selection of the value stream to theestablishment of a final action plan.

� Wastes that may be reduced or eliminated, tak-ing into account predicted changes in physicalrisk factors.

Future state:

� Visualization of a hypothetical, desirable futurestate, where considerations to waste reductionand ergonomics are duly balanced

� an action plan of interventions to realize thefuture state

4.4. Ratings

Five ergonomics issues are considered in ErgoVSM,four of which are pertinent to the current value stream;i.e. postures (Section 4.4.1), forces (Section 4.4.1),physical variation (Section 4.4.3), and porosity (Sec-tion 4.4.4). In addition, as a fifth issue, ErgoVSMaddresses the potential for arriving at a future statevalue stream with good ergonomics (Section 4.4.2).

Assessment scales for each of these issues are gradedfrom 1 to 10, as shown in Figures 3 and 4 and 6–8.Larger scores indicate more negative conditions.

4.4.1. Postures and Forces in the Tasks

Assessments of postures and external forces are basedon the assumption that they should be treated as in-dependent risk factors in an ergonomics interventionprocess (e.g., van der Beek & Frings-Dresen, 1998).However, if awkward postures occur together withlarge external forces, this results in a potentiation oftheir effects, as predicted by standard biomechanics (cf.Chaffin, Andersson, & Martin, 2006). Thus, in Er-goVSM, postures and forces at the task level are initiallyassessed by using independent rating scales for posturesand forces in each separate task (Figures 3 and 4). Theassessment scales for postures and forces were inspiredby the WEST (Work Environment Screening Tool)



Figure 3 The rating scale for assessing postures in the tasks.

Figure 4 The rating scale for assessing weight/force in the tasks.

(Brohammer & Karling, 2002). These ratings allow foridentification of ergonomics problems specifically re-lated to either force or postures associated with a par-ticular task.

The effect of postures and forces is then assessedfor each task by multiplying the posture and force

ratings so as to give a combined rating correspondingto the external torque associated with the task. The re-sulting product, which can take values between 2 and100, is multiplied by the duration of the task. These“torque-time” products are added across all tasks inthe value stream. The resulting sum is then divided



by the total duration of the value stream. Finally, thistime-weighted torque index, representing an averagetorque across tasks, undergoes a square root transfor-mation, so as to have it operating on a 10-point scaleequivalent to that used for the other issues addressedby ErgoVSM.

4.4.2. Ergonomics Potential of the ValueStream

The ergonomics potential is defined as the diversity inphysical exposure between tasks in the value stream,that is, the extent to which tasks differ in exposure(cf. Mathiassen, 2006). It describes the potential forobtaining variation in physical exposures for the op-erators. Each task is classified according to one of sixcategories (A to F) on the basis of their exposure char-acteristics (Figure 5). The categorization is based onposture (sitting, standing, or walking) and occurrenceof manual material handling. Tasks in Category A rep-resent a low risk for MSD and can be performed forextended periods, although not without interruption.Categories B to E represent different combinations ofwhole-body postures and manual handling, which aresufficiently different from one another to offer physicalvariation when combined. Category F represents heavywork, both in terms of postures and loads.

The ergonomics potential in the value stream is as-sessed by first identifying the number and total dura-tion of tasks in each category (A to F). The assessmentof the ergonomics potential is then performed on basisof the criteria illustrated in Figure 6, without consider-ing how tasks are distributed between operators in thecurrent state.

4.4.3. Physical Variation at the Job Level

Physical variation is addressed in ErgoVSM by evaluat-ing the variation between jobs carried out by individualworkers in the value stream. First, the distribution be-tween operators of available tasks in the value stream isdescribed in the current state, using the task CategoriesA to F in Figure 5, combined with the duration of thesetasks in each operator’s job. Physical variation at thevalue stream level is then rated according to Figure 7,on the basis of an overall assessment of the jobs of alloperators.

4.4.4. Porosity of the Value Stream

Porosity is defined as the proportion of working timethat can offer an opportunity for physical recovery.

The extent to which the operators can control whento schedule recovery is also considered. Porosity mayoccur both within and between tasks. Both aspects areconsidered in the rating of porosity, which is attemptedto show the average situation for all operators in theinvestigated value stream. The assessment of porosityis performed according to Figure 8.

5. APPLICATION OF THE ErgoVSMTOOL5.1. Material and Method

Following the development of the ErgoVSM tool incooperation with three manufacturing companies (seeSection 4.1), we tested it in full scale at a fourth Swedishmanufacturing company, a subcontractor to the car in-dustry. The selected value stream comprised manufac-turing of a plastic component and the following fivetasks: dryer, injection molding, hanging goods for thecoating process, picking off goods, and assembly. TheVSM was adapted to the prevailing procedure in thecompany.

Three groups, each including four experienced op-erators (two men, two women) from the selected valuestream, completed the analyses independent of oneanother. The groups were named VSM, ErgoVSM-1,and ErgoVSM-2 (Table 1). The lean coordinator of theplant, who was a production engineer with experiencein VSM, guided the three groups during the analy-ses. None of the operators were acquainted with VSMwhen recruited into the groups. In addition to the leancoordinator, an additional production engineer partic-ipated in each of the ErgoVSM groups to learn aboutthe new tool.

The VSM-group carried out a traditional VSM with-out the ergonomics complement, and the two othergroups (ErgoVSM-1 and ErgoVSM-2) carried outErgoVSM. The three groups were working in differ-ent shifts to avoid spillover effects.

First, all three groups received a 1-day VSM trainingcourse. Next, the VSM-group conducted VSM of thecurrent state and developed future state, while the twoErgoVSM groups received an additional 1-day train-ing course specifically in ErgoVSM. Finally, these twogroups performed an analysis of current state and de-veloped future state using ErgoVSM.

The ErgoVSM training course was led by one of thepresent authors (CJ). In each of the three groups, theanalysis and discussion process was observed by at least



Figure 5 The categories (A to F) used to classify the tasks in the value stream.

Figure 6 The rating scale used to assessing the ergonomics potential offered by the value stream on basis of a classificationof the constituent tasks using the categories shown in Figure 5.

one member of the research team to assess whether anysignificant deviations occurred from common VSMprocedures, apart from the intended ergonomics com-plement in the ErgoVSM groups. The discussions inthe three groups were video-filmed, except for shortperiods spent in the production shop to answer ques-tions regarding production details, for example, theduration of some tasks. The video films were later usedby the researchers to facilitate understanding of thereasoning.

All groups had their work based in a conferenceroom. In addition, they performed observations andcollected data in the production shop, and they madephone calls to get information from, for example, pur-chasers regarding material quantities and frequenciesof delivery. All three groups performed their analyseswithin a time frame of, in total, 5 weeks.

5.2. Results

5.2.1. Development of Proposals for theFuture State

The VSM group developed proposals and solutions forthe future state directed by the aim of minimizing leadtime. No major changes were suggested to the valuestream, neither regarding work processes nor manning.The VSM group used, in total, 18 hr for training, andproducing a current state, a preferred future state andan action plan.

Both ErgoVSM groups had comprehensive discus-sions on how to change the value stream, includingconsiderations of ergonomics issues. This implied thateach of these groups needed an additional 6 hr (i.e.,24 hr in total). The ErgoVSM-1 group initially sug-gested placing an available robot in the injection



Figure 7 The rating scale used to assess physical variation in the job of the operators in the value stream. Observe thatthis score cannot exceed the score for “ergonomics potential” (Figure 6).

Figure 8 The rating scale used to evaluate the porosity in the value stream.

molding. However, when looking at the ergonomics as-sessments, they came to the conclusion that the robotshould rather be placed in assembly to improve er-gonomics there. The same group also suggested toradically reduce manning. Arguments of the operatorswere as follows: “We can do everything—away withthe planners—we can do the planning of productionourselves” and “I can do everything—except drive thetruck.”

5.2.2. Impact on Performance

All three groups managed to reduce lead time from 25to 30 days in the current state to 7–8 days in the future

state (Table 1). This was mainly due to changes in thematerial planning system where large stocks were sub-stituted by small buffers. Thus, the duration of VAAwas almost the same for all three groups for both cur-rent and future states. Both groups using ErgoVSMreduced the manual working time from 2 to about1 min.

5.2.3. Impact on Ergonomics

Tables 2–4 summarize the ergonomics assessmentsin current and future states made by the twoErgoVSM groups. At the task level, both groups



TABLE 1. Total Lead time, duration of value-adding activities (VAA) and duration of manual working time (i.e. VAW +non-VAW) as determined by the VSM, ErgoVSM-1, and ErgoVSM-2 Groups

VSM ErgoVSM-1 ErgoVSM-2

Current State Future State Current State Future State Current State Future State

Lead time 28.9 days 8.2 days 24.6 days 7.2 days 25.0 days 8.5 daysDuration of VAAa 75 s 75 s 85 s 85 s 79 s 79 sDuration of

manualworking time

Not assessed in VSM Not assessed in VSM 102 s 71 s 114 s 50 s

Note: aThe indicated durations do not include time for the processes dryer and hanging goods for coating, as these werenot assessed by the groups.

TABLE 2. Ergonomics Assessments at the Task Level (cf. Figure 2 and 3) for Current and Future State of the value stream,made by the two ErgoVSM groups. If the task is classified in two categories (column “task category”) due to physicalexposure diversity within the task, the underlined letter represents the dominating category. “Posture rating”: see Figure3; “Force rating”: see Figure 4; “Task Category”: see Figure 5. “Manual working time”: duration of VAW + non-VAW

ErgoVSM-1 ErgoVSM-2

Task State

ManualWorkingTime (s)

PostureRating

ForceRating

TaskCategory

ManualWorkingTime (s)

PostureRating

ForceRating

TaskCategory

Dryer Present 2 7 5 A, F 4 8 5 F, BFuture 1 2 2 A 2 5 2 C, B

Injection Present 3 2 3 C 3 3 3 E, Cmolding Future 2 1 2 A 2 3 3 E, C

Hanging Present 11 3 3 A, E 22 4 3 E, Agoods Future 7 3 3 A, E 5 4 3 E, A

Picking off Present 15 3 3 A, E 18 3 3 E, Agoods Future 12 3 3 A, E 9 3 3 E, A

Assembly Present 71 4 3 A, E 68 2 2 EFuture 50 4 3 A, E 32 2,5 2 E

suggested changes, so that duration of manual work-ing time (i.e., Duration of VAW + Non-VAW) wouldbe reduced in the future state for all tasks with-out negatively affecting neither posture nor force;for one task (dryer) both posture and force wereeven rated to be improved (Table 2). At the valuestream level, both ErgoVSM groups suggested inter-ventions that were judged to improve both expo-sure level and ergonomics potential (Table 3), andat job level, both groups suggested interventions esti-mated to lead to increased variation in the future state(Table 4).

TABLE 3. Ergonomics assessments at the Value streamlevel for Current and Future State of the value stream, madeby the two ErgoVSM groups. “Exposure Level”: see papersection 4.4.1; “Ergonomics potential”: see Figure 6; “Poros-ity”: see Figure 8

Value stream State ErgoVSM-1 ErgoVSM-2

Exposure level Current 3,4 2,8Future 3,3 2,6

Ergonomics potential Current 4 8Future 3 6

Porosity Current 4 4Future 4 3



TABLE 4. Ergonomics assessments at the Job level for Cur-rent and Future State of the value stream, made by the twoindependent ErgoVSM groups. “Job variation”: see Figure 7

Job level State ErgoVSM-1 ErgoVSM-2

Job variation Current 6 9Future 3 6

6. DISCUSSIONThe developed ErgoVSM tool seems to be usable forproduction engineers and experienced operators. Byfeeding discussions in operator groups, it catalyzedidentification of intervention proposals, consideringboth production and ergonomics. Improvements inproduction performance were achieved to the sameextent by traditional VSM and ErgoVSM, while thelatter also included proposals for improved workingconditions.

6.1. From Science to Practice

Numerous studies have emphasized that worker par-ticipation and a dialogue between workers and man-agement are crucial prerequisites for success whencarrying out interventions for developing sustainablesystems (Hignett, Wilson, & Morris, 2005; Westgaard& Winkel, 1997, 2011). Participation is also an impor-tant factor in determining the success of ergonomicsinterventions (Rivilis et al., 2008). Several key issues ofparticipation seem to be fulfilled already in traditionalVSM (Haines, Wilson, Vink, & Koningsveld, 2002), andthis was part of the reason for selecting VSM as the ra-tionalization tool to which an ergonomics complementshould be developed.

A recent review of ergonomics intervention researchconcluded that most studies have focused interven-tions for the individual worker (Westgaard & Winkel,2011). The authors concluded that individualized in-tervention seems to have limited health effects in along-term perspective. Following this, Westgaard andWinkel (2011) reviewed the literature to identify mus-culoskeletal and mental health effects of productionsystem rationalization as well as organizational-levelmeasures that may modify such relationships. Theyconcluded that rationalizations often result in impairedergonomics, and therefore, they suggested that “toolsand methodologies should be developed that allowconcurrent tuning of performance and wellbeing con-siderations in a rationalization process” (Westgaard &

Winkel, p. 289). On this background, we developed thepresent tool.

ErgoVSM is unique in the sense that ergonomicsevaluations are embedded in the traditional VSM toolfor rationalization. Thus, ordinary users of VSM maytake on ErgoVSM instead. As stakeholders developingproduction systems are the main agents in creatingwork environment problems (cf. Westgaard & Winkel,2011), it seems reasonable to complement one of theirmain rationalization tools by work environment issuesto promote development of more sustainable systems.Thereby, ergonomics is handed over from the tradi-tional ergonomists to those working on significant as-pects of the production system performance. Further-more, choosing VSM as the backbone of ErgoVSM wasalso motivated by the fact that VSM is a participatoryprocess tool used by those being exposed themselves tothe resulting interventions. A higher level of ownershipto the changes may thus be obtained (cf. Westgaard &Winkel, 1997). On this background, the present er-gonomics complement to the VSM tool introduces anextra step on the way to the final action plan; the groupis stimulated to consider potential consequences ofwaste reduction proposals in terms of ergonomics riskfactors for the operators before the proposals are in-cluded in the final action plan. Whether the individualassessments are exactly correct and valid thus becomesless important. The main issue is if they agree whetherthe proposals may improve or impair ergonomics. Thispoint is illustrated by the fact that the two ErgoVSMgroups had slightly different quantitative ratings of thesame value stream (cf. Tables 2–4) but had similar suc-cess in identifying a future state value stream that wasboth more effective and less ergonomically demandingthan the current state.

6.2. Methodological Discussion

6.2.1. Factors Assessed by ErgoVSM

In general, the duration of analyzed tasks in a valuestream is short (cf. Table 1). The risk for an in-dividual operator of contracting MSD depends on1) the exposure of individual tasks, 2) the distributionof tasks between operators within the value stream, and3) differences in exposure between the tasks. The twolatter issues are considered by the ErgoVSM ratings ofergonomics potential and job variation. Furthermore,an operator may perform tasks in other value streamsas well to make up a full job. This latter issue should



be considered by applying the ErgoVSM tool for allrelevant value streams. The first issue, exposure level,is assessed by rating postures and forces for all tasks inthe value stream and combining those ratings with taskdurations. Thus, high ratings of posture and/or forcein a particular task may result in a minor contribu-tion to the exposure level of the whole value stream ifthe duration of that task is comparatively short. In thepresent test of ErgoVSM, the two groups assessed theduration of manual working time for the current stateslightly different for some of the tasks (e.g., hanginggods, see Table 2). However, this could be explainedby the fact that one group assessed the time by using aclock, while it was just estimated by the other group.

Several field studies have agreed that current ratio-nalization in manufacturing industry generally causes awork intensification (Burchell et al., 2002; Eurofound,2012; Green, 2004; Westgaard & Winkel, 2011), in thesense that “breaks” between tasks are eliminated whileposture and/or force demands in active work changesonly little (e.g., Ostensvik et al., 2008; Palmerud et al.,2012). Rating of porosity was included in the ErgoVSMtool to make the operators aware of this potential risk.

6.2.2. Application of ErgoVSM

The present pilot evaluation of the ErgoVSM tool doesnot allow for any statistical analyses. It supports, how-ever, that a potential pathway for future ergonomicsinterventions can be a shift of the responsibility forthe practical work on ergonomics interventions fromergonomics “experts” to the line organization and pro-duction planning department.

The present application of the ErgoVSM tool bythe two groups in the test company showed that bothmanaged to reduce the estimated duration of manualworking time in the future state. In both groups, thisreduction was obtained with unchanged or even re-duced estimated occurrence of risk factors in the in-dividual tasks, even though the groups chose differentsolutions for the future state value stream. Thus, theErgoVSM tool proved successful in catalyzing a changeprocess, which was positive from an ergonomics pointof view, even if the possible added ergonomics valuebeyond that obtained when using standard VSM wasnot assessed. The observed changes could, in theory,have been influenced by the researchers, who have avested interest in the ErgoVSM tool. We believe, how-ever, that this possible influence was marginal, sincethe change process followed a detailed, prescribed pro-

cedure. Thus, the suggested ergonomics interventionswere mainly motivated by the participants’ scorings,which were not influenced by the researchers. To under-stand these possible benefits in more detail, the presentpilot evaluation of the ErgoVSM tool needs to be com-plemented by more comprehensive comparisons of theresults of using ErgoVSM compared to standard VSM.

7. CONCLUSIONSThe current study addressed the integration of er-gonomics aspects into the lean rationalization toolVSM by developing an ergonomics module to VSM.This ErgoVSM tool turned out to have a reasonableapplicability for the intended target group and ap-peared to successfully catalyze change processes, result-ing in proposals for revised value streams that consid-ered both ergonomics and waste reduction. The use ofErgoVSM required some more time than a traditionalVSM. However, the resulting solution for a future stateof the value stream presented estimated ergonomicsimprovements without any negative effects on the es-timated production performance.

8. FURTHER RESEARCHThe present version of ErgoVSM needs further devel-opment and evaluation compared to the use of VSMonly. This should include further tool developmentand simplification to increase applicability and po-tential impact. Psychosocial factors of importance tohealth and well-being should also be included in thetool (cf. Mejıas Herrera & Huaccho Huatuco, 2011).In addition, knowledge is needed on contextual fac-tors affecting the implementation of ErgoVSM, forexample, to what degree the results depend on theindividual researcher and/or lean coach. All these is-sues are at present addressed in a Nordic multicenterstudy (Winkel et al., 2012) to facilitate developmentof more “sustainable” production systems within thehealthcare sector.

ACKNOWLEDGMENTSThis work was conducted with the financial supportof the Swedish Governmental Agency for InnovationSystems, VINNOVA (2002-01962), and AFA Insurance(070084). We thank all the operators and production



engineers from the cooperating companies who madethis study possible.

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