Production Ergonomics Evaluation – Needs, Procedures and Digital Human Modeling Tools
Licentiate thesis, 2009
In production systems, human operators may be at risk for developing work-related
musculoskeletal disorders (MSDs), resulting in pain, inability to work and high costs. An
increasingly capable tool for identifying MSD risks early in the production design
process are Digital Human Models (DHMs), although their built-in analysis tools are in
great need of development regarding how they address time-related aspects of load
exposure. Some examples of time-related exposure phenomena provoking MSDs are
repetitive work patterns, lack of variation, fatigue effects, work rotation effects, and
distributions of activity/rest. The aim of this thesis is therefore two-fold; to explore
pragmatic industrial needs regarding ergonomics evaluation and compare this to the
State-of-the-art of scientific evaluation methods that address time-related aspects.
The first approach, a case study in an automotive setting, revealed that switching from
one evaluation method to another in a factory may be for pragmatic contextual reasons
rather than based on educated selection. It was also shown that companies who do this
may unintentionally risk producing evaluation results that are not equal regarding
criteria levels or degree of analysis detail, rendering results unsatisfactory to use for
some actors in the process.
The second approach, a literature review, categorizes several time-related ergonomics
terms and has proposed a ‘process-flow’ framework for the terms, based on an inputthroughput-
output concept. This framework can give DHM tool developers an overview
of which time-related aspects interact and which combinations are suited to different
Lastly, the thesis reflects on actor roles and time perspectives.
Digital Human Modeling