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GfA, Dortmund (Hrsg.): Frühjahrskongress 2018, Frankfurt a. M. Beitrag D.1.6
ARBEIT(s).WISSEN.SCHAF(f)T – Grundlage für Management & Kompetenzentwicklung
1
Work system analysis for the user-centered development
of cooperative mobile robots
Benedikt LEICHTMANN1, Florian SCHNÖS2, Philipp RINCK2,
Michael ZÄH2,Verena NITSCH1
1 Human Factors Institute (IfA), University of the Bundeswehr Munich
Werner-Heisenberg-Weg 39, D-85577 Neubiberg
2 Institute for Machine Tools and Industrial Management
Technical University of Munich
Boltzmannstraße 15, D-85748 Garching bei München
Abstract: One of the main goals of the collaborative research project
FORobotics is to gain new insights into human-related aspects and pro-
cesses that might be essential to the development and effective imple-
mentation of cooperative mobile robots. In order to achieve this goal, a
qualitative, task-related work system analysis was conducted as a first
step. This analysis served to identify potentially relevant context-related
aspects that need to be considered in early stages of the development
process. Four work systems in three companies were analyzed that in-
cluded order-picking, manufacturing and assembly tasks. For the analysis,
a method was devised based on different modules of RIHA/VERA (Oester-
reich, Leitner, & Resch, 2000) and KOMPASS (Grote, Wäfler, Ryser, &
Weik, 1999). As such, it comprised document analyses, workplace obser-
vations, semi-structured interviews and questionnaires. Further modules
assessing technical aspects were developed and added. In a multi-
disciplinary workshop, development recommendations were formulated
based on the data analysis and taking into account the KOMPASS criteria
(Grote et al., 1999) and additional criteria for designing human-machine in-
teraction (Klein, Woods, Bradshaw, & Feltovich, 2004). The recommenda-
tions addressed topics such as robot equipment, robot movement and
path planning, function allocation and task planning, and interface design.
Keywords: work system analysis, qualitative analysis, human factors,
human-robot interaction, applied psychology
1. Introduction: Work system analysis
Industrial workplaces at which people work closely with robots offer the opportunity
to combine human skills with the precision and endurance of robots to make produc-
tion more efficient and at the same time reduce the cognitive and physical workload
for humans. Since there are no physical barriers that would protect humans from col-
lisions with the robot, it is necessary to create a usage concept for these workplaces,
which does not impact on safety, productivity or user acceptance in a negative way.
However, as of yet, systematic research efforts that would provide an empirical basis
for the development and employment of worker-friendly cooperative robots are rare.
One of the main goals of the collaborative research project FORobotics is, therefore,
to gain new insights into crucial aspects of mobile human-robot interaction in indus-
trial work settings (http://www.forobotics.de/, 2017).
GfA, Dortmund (Hrsg.): Frühjahrskongress 2018, Frankfurt a. M. Beitrag D.1.6
ARBEIT(s).WISSEN.SCHAF(f)T – Grundlage für Management & Kompetenzentwicklung
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Prior to the development and implementation of a new technology, such as coop-
erative robots, an analysis of the work environment and potential use context is es-
sential. Introducing innovations into the workplace can lead to unintended negative
consequences (e.g. Tenner, 1997), such as increased stress levels or reduced
productivity (Tarafdar, Tu, & Ragu-Nathan, 2010), in particular, if the use context is
not taken into consideration. Rather than investigating specific user characteristics or
task requirements in isolation, an analysis of the whole work system, in which the
technology is to be employed, is preferable. Work systems, as described in work
psychology and ergonomics, are dynamic, socio-technical and highly interlinked open
systems (Brauchler & Landau, 1998) that include one or several workers, equipment,
functions, tasks and environmental factors within a workspace (DIN Deutsches Insti-
tut für Normung e.V., 2016).
Following the user-centered design approach as stipulated by DIN EN ISO 9241-
210 (DIN Deutsches Institut für Normung e.V., 2011), research in the FORobotics ini-
tiative featured a comprehensive analysis of potential work systems in the production
sector, in which mobile cooperative robots might be employed. For this purpose, a
qualitative work system analysis was conducted in order to provide recommendations
and a basis for empirically well-grounded decision-making for the human-centered
development of cooperative mobile robot platforms.
2. Methods
As a first step, an analysis tool kit was devised on the basis of defined criteria. The
appropriate tool kit was to provide a conditional work analysis (as opposed to a per-
sonal analysis), i.e. the focus should be on the task and environment, not on the in-
vestigated workers. Furthermore, the tool should constitute an expert method and not
a screening method as the respective activities should be recorded as precisely as
possible in order to be able to give well-grounded recommendations. As a third crite-
rion, the analysis should focus on production, assembly and order-picking operations
as opposed to office work. Beyond that, the tool should meet basic scientific criteria
such as reliability and validity.
2.1 Materials
The devised analysis tool kit was mainly based on the KOMPASS method (Grote
et al., 1999) and further complemented by several modules of the RIHA/VERA meth-
od (Oesterreich et al., 2000). From both methods, individual modules were selected
which were most suitable for the purpose of giving design recommendations for mo-
bile cooperating robots. Both analysis methods are based on qualitative research
methods such as workplace observations, semi-structured interviews and documents
analysis. The analysis tool KOMPASS by Grote et al. (1999) is theoretically based on
a complementary system design approach with focus on human and machine as an
interaction with reciprocal dependencies rather than separable entities. The analysis
with KOMPASS is based on three levels (i.e. work system, task of human operator
and the human-machine-system) and can be used for existing work systems as well
as prospective analysis of planned work systems – as it is the case for FORobotics.
The criteria for the analysis have been empirically tested with regard to reliability and
validity (Grote, Ryser, Wäfler, Windischer, & Weik, 2000).
The RIHA/VERA method (specifically the version which focuses on work condi-
GfA, Dortmund (Hrsg.): Frühjahrskongress 2018, Frankfurt a. M. Beitrag D.1.6
ARBEIT(s).WISSEN.SCHAF(f)T – Grundlage für Management & Kompetenzentwicklung
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tions in the production sector) is based on the action regulation theory and has been
empirically tested through double analyses (Oesterreich et al., 2000). Only modules
of RIHA/VERA were used that added information on aspects not considered by
KOMPASS (such as non-machine equipment). It thus complemented the KOMPASS
method, which focuses on human-machine interaction in more detail than RI-
HA/VERA. In order to assess equipment, instruments and technical tools in more de-
tail, single modules of RIHA/VERA were modified and extended.
2.2 Analysis Procedure
Three companies in the production sector that aim to introduce a mobile ad-hoc
cooperating robot platform into their respective work systems provided access to four
different work systems for the analysis. The four work systems included the tasks of
production (1 system), order-picking (1 system) and assembly (2 systems) and were
all situated in Germany. The analyses were carried out independently of each other
by a team of two trained experts as observers with at least two workers each carrying
out the same activity. Such a procedure is, according to Oesterreich & Bortz (1994),
the strictest method for ensuring a reliable procedure, as it allows to better control the
error variances stemming from the observer and the analyzed manufacturer. Thus,
each work system was analyzed at least two times with different workers. In total, da-
ta of ten workers were obtained in this study. First, qualitative and quantitative data
were collected using the tool kit described above. Afterwards, the observation data
were validated in semi-structured interviews with the observed persons. After the in-
terviews, the participants were encouraged to ask questions or to add further com-
ments. In consultation with the respective companies, image and video data could be
collected during the analysis. In addition, the analysts were provided with company-
internal documents for document analysis. The evaluation of the data was carried out
according to data protection regulations and only by the respective executing ex-
perts.
3. Results and discussion
A workshop on the qualitative analysis of the results was carried out based on the
recommendations of the KOMPASS manual. The respective analysts, consisting of a
team of two psychologists and a team of two engineers, participated in the workshop.
In a first step, a common ground was created by clarifying technical terms and the
criteria for a humane design of human-robot cooperation according to Grote et al.
(1999, see KOMPASS criteria) and criteria for the design of human-robot teams ac-
cording to Klein, Woods, Bradshaw, Hoffman and Feltovich (2004), as well as Chris-
toffersen and Woods (2002). Subsequently, potentials and risks for each of the four
analyzed work systems were identified from the data by identifying potential contribu-
tions from humans and a potential robot system. In a third step, design recommenda-
tions were derived taking into account the above-mentioned criteria for each work
system.
3.1 Beneficial and obstructive contributions of humans in the work system
Among the identified beneficial human contributions (compared to the robot sys-
tem) is the performance of more delicate tasks. This had been observed in the case
GfA, Dortmund (Hrsg.): Frühjahrskongress 2018, Frankfurt a. M. Beitrag D.1.6
ARBEIT(s).WISSEN.SCHAF(f)T – Grundlage für Management & Kompetenzentwicklung
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of pre-assembly activities: Rubber seals had to be attached before one of the as-
sembly parts was fitted into a set plate. In addition, changing environmental condi-
tions or unusual new situations were found during observations, with which humans
can currently cope better than machines. For example, it had been observed that
some under-specified orders or special features of assembly orders required consul-
tation with a supervisor or needed an inter-collegiate exchange. This also includes
corrective actions and lack of information. For instance, there were no descriptions
on the layout template for the arrangement of set plates, but this could be compen-
sated by the experience of the work force. In addition, humans are able to not only
compensate for missing information, but also process different materials and infor-
mation. Furthermore, non-systematized practices are often found in small and medi-
um-sized companies in particular. In one example, information on the status or loca-
tion of a product was sometimes passed on to the next worker by a handwritten note
at the respective location in the rack ("[Product number] at [Worker-name] in the as-
sembly area"). Movable obstacles were frequently encountered. For example,
transport trolleys had been parked in the hallway (found in all work systems), people
were standing in narrow aisles, work areas were already occupied or product parts
protruded from shelves (e.g. in the warehouse) and thus narrowed the way. Human
workers are generally better able to identify, classify, circumvent or even eliminate
such obstacles than a robot system at the current state of the art.
On the other hand, potentially obstructive contributions of human workers were
identified. First of all, part of the variance in the environment was found to be the re-
sult of unstructured or inaccurate work and thus caused by humans. For example,
discrepancies in the arrangement of workplaces could be found in cases where the
arrangement was either not prescribed or where regulations were circumvented. This
often led to unnecessary searching behavior, especially at workplaces that were
used by several workers. Another hindering aspect of humans can be the conse-
quences of constant under- or overload in the form of performance losses or dissatis-
faction. Underload can be the consequence of lacking or low planning and decision-
making requirements. In three of the four work systems, at least partial tasks could
be identified that only require very little planning or mental effort (e.g. pure sensory
motor regulation when arranging individual parts in a set plate) or only minor planning
and decision-making requirements, such as the mere visualization of working steps
during assembly or commissioning activities. Only in one work system, the planning
and decision-making requirements had been found to be moderate, since the ad-
justment of machine functions sometimes required workers to adjust pre-defined
plans. However, overall, planning and decision-making requirements were limited.
The tasks thus scored low on the task completeness criterion of KOMPASS. For the
evaluation of monotony, in addition to the mental demand, the uniformity and how
much the task is capturing the workers attention was examined. One working system
was evaluated as at least partially and another as clearly monotonous. Monotonous
work could lead to fatigue and may result in errors, and is thus inappropriate for hu-
mans.
3.2 Beneficial an obstructive contributions of robots
With respect to monotony, a robot system can contribute positively by carrying out
monotonous work and facilitate work in ergonomically unfavorable positions. For ex-
ample, in one work system, little motors had to be mounted on a steel ring. The steel
GfA, Dortmund (Hrsg.): Frühjahrskongress 2018, Frankfurt a. M. Beitrag D.1.6
ARBEIT(s).WISSEN.SCHAF(f)T – Grundlage für Management & Kompetenzentwicklung
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ring had to be turned around by an electronic lifter, so that the human operator would
be able to mount the motors. A robot system would be better able to mount motors
without lifting the heavy steel ring, as it can operate in different positions. Also, robot-
ic systems can be used for automated documentation of the quality inspection. It was
found that human workers sometimes write down less accurate numbers or circum-
vent cut-off criteria when the measurement was found to be close to the cut-off. Con-
cerning the quality of work, robots may have beneficial contributions when it comes
to accuracy, e.g. in positioning or dosing. In addition to this, quality in structured
tasks may be higher, because of more systematic searching behaviors in structured
problem spaces. During the assembly task, it was observed that a worker had to go
to the warehouse, because an assembly part was missing. A robot would be able to
take on such unnecessary walking distances while humans can continue with the
main task. Under certain conditions, a robotic system can also serve as an extension
of the requirements profile and task spectrum for human workers and reduce monot-
ony.
As a negative consequence, the allocation of functions to robots can also reduce
the completeness and variety of tasks by the sole allocation of monitoring or trouble-
shooting activities to humans. This is the case when the robot system takes over the
main tasks and the human operators' tasks are limited to checking the system and
correcting errors if necessary. Then again, the monotonous activity is only shifted,
when the human worker is only busy with assembling those parts, with which the ro-
bot system cannot cope. Finally, it should be noted that a robot platform itself can be
a source of error. As mentioned above, aisles were often found to be narrow and a
robotic system itself can thus be an obstacle for the human operator, especially when
it only moves slowly because of safety reasons and hence is slowing down the hu-
man operator. Robots have also oftentimes difficulties in unstructured environments
and handling complex materials. For example, in a company with a small production
batch but a big variety of the products, a lot of different materials had to be handled
including heavy and bulky pieces with sharp edges. A transportation aid especially of
products of such kind would be of assistance for humans, but cannot necessarily be
accomplished by robots yet.
3.3 Design recommendations and summary
Based on the identification of beneficial and obstructive contributions of human
and machine, specific design recommendations for the subsequent development of
mobile cooperating robot platforms in FORobotics were derived. Concerning the abili-
ties, the robot system should be able to locate, grab, handle and transport different
materials in different orientations and positions or in confined spaces. Furthermore, it
should have the ability to overcome small steps and to carry out swiveling move-
ments in a small space. Regarding function allocation, it was found that monotonous
tasks are not easily allocated to robots, without shifting monotony or running the risk
of restricting the completeness of work. Furthermore, for joint planning activities, it
would be advantageous if the system could explain plans to the worker, as s/he
sometimes asked for more information in special cases. With regard to the human-
robot interface, it should be taken into consideration that in most environments, safe-
ty devices such as ear protectors are used due to noise or gloves due to sharp-
edged materials, which limits the ability of the worker to communicate with a system
to certain channels. Therefore, an interface based on speech input is less suitable
and touch screens must also be well considered. Communication via gestures or
GfA, Dortmund (Hrsg.): Frühjahrskongress 2018, Frankfurt a. M. Beitrag D.1.6
ARBEIT(s).WISSEN.SCHAF(f)T – Grundlage für Management & Kompetenzentwicklung
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movement cues would be more suitable. Clearly, the robot system should provide
missing information that would otherwise be lost when using the system. In the case
of robotic work in unfavorable positions, for example, human operators may lack in-
formation about the progress of the process. Finally, it has to be mentioned that a
negative attitude towards robots in general (e.g. fear of change in work practices) be-
came apparent in the unstructured interviews. This points to the importance of ac-
companying the introduction of new technologies, such as cooperative robots, with
appropriate change management procedures, if this technology is to be introduced
into existing work systems successfully.
4. References
Brauchler, R., & Landau, K. (1998). Task analysis: Part II - The Scientific Basis (knowledge base) for
the guide. International Journal of Industrial Ergonomics, 22, 13–35.
Christoffersen, K., & Woods, D. D. (2002). How to make automated systems team players. In E. Salas
(Ed.), Advances in Human Performance and Cognitive Engineering Research (Vol. 2, pp. 1–12).
St. Louis: Elsevier Science.
DIN Deutsches Institut für Normung e.V. (2011). Ergonomie der Mensch-System-Interaktion - Teil 210:
Prozess zur Gestaltung gebrauchstauglicher interaktiver Systeme. (DIN EN ISO 9241-210:2010).
DIN Deutsches Institut für Normung e.V. (2016). Grundsätze der Ergonomie für die Gestaltung von
Arbeitssystemen. (DIN EN ISO 6385:2016).
Grote, G., Ryser, C., Wäfler, T., Windischer, A., & Weik, S. (2000). KOMPASS: A Method for Com-
plementary Function Allocation in Automated Work Systems. International Journal of Human-
Computer Studies, 52, 267–287.
Grote, G., Wäfler, T., Ryser, C., & Weik, S. (1999). Wie sich Mensch und Technik sinnvoll ergänzen:
Die Analyse automatisierter Produktionssysteme mit KOMPASS. Mensch, Technik, Organisation:
Vol. 19. Zürich: vdf Hochsch.-Verl. an der ETH.
Klein, G., Woods, D. D., Bradshaw, J. M., & Feltovich, P. J. (2004). Ten challenges for making auto-
mation a "Team player" in joint human-agent activity. IEEE Intelligent Systems, 19(6), 91–95.
Oesterreich, R., & Bortz, J. (1994). Zur Ermittlung der testtheoretischen Güte von Arbeitsanalysever-
fahren. ABO-aktuell, 3, 2–8.
Oesterreich, R., Leitner, K., & Resch, M. (2000). Analyse psychischer Anforderungen und Belastun-
gen in der Produktionsarbeit: Das Verfahren RHIA/VERA-Produktion: Hogrefe.
Tarafdar, M., Tu, Q., & Ragu-Nathan, T. S. (2010). Impact of Technostress on End-User Satisfaction
and Performance. Journal of Management Information Systems, 27(3), 303–334.
Tenner, E. (1997). Why Things Bite Back: Technology and the Revenge of Unintended Consequences
(1. Vintage Books ed.). New York: Random House.
Acknowledgement: This research was supported by the Bavarian Research Foun-
dation. The authors wish to thank Anabel Rohde for her assistance in the observa-
tions and interviews.
Gesellschaft für
Arbeitswissenschaft e.V.
ARBEIT(S).WISSEN.SCHAF(F)T
Grundlage für Management & Kompetenzentwicklung
64. Kongress der
Gesellschaft für Arbeitswissenschaft
FOM Hochschule für
Oekonomie & Management gGmbH
21. – 23. Februar 2018
Press
Bericht zum 64. Arbeitswissenschaftlichen Kongress vom 21. – 23. Februar 2018
FOM Hochschule für Oekonomie & Management
Herausgegeben von der Gesellschaft für Arbeitswissenschaft e.V.
Dortmund: GfA-Press, 2018
ISBN 978-3-936804-24-9
NE: Gesellschaft für Arbeitswissenschaft: Jahresdokumentation
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