Peter Thorvald

Manufacturing in the wild – viewing human-based assembly through the lens of distributed cognition

Abstract The interdisciplinary field of cognitive science has been and is becoming increasingly central within human factors and ergonomics (HF&E) and, since at the same time, there has long been a call for a more systems perspective in the area with a somewhat wider unit of analysis. This paper argues that the theoretical framework of distributed cognition would greatly benefit the application of HF&E to manufacturing and would offer a more holistic understanding of the interactions between different entities within a greater context, including the social, cultural and materialistic. We aim to characterize and analyse manufacturing as a complex socio-technical system from a distributed cognition perspective; focusing on the use, mediation and integration of different forms of representations, tools and artefacts in this domain. We present illustrative examples from authentic manual assembly, showing the cognitively distributed nature of the work, ranging from scaffolding strategies of the individual worker to the emergent properties of a whole assembly line. The paper further proposes and provides benefits of using a distributed cognition framework as a novel approach in the toolbox for the HF&E discipline, where it may have been found before, but the application to manufacturing has been absent.

Interruptions in the wild: portraying the handling of interruptions in manufacturing from a distributed cognition lens

This paper presents a study examining interruptions in the wild by portraying the handling of interruptions in manufacturing from a distributed cognition lens. By studying how interruptions occur and are handled in the daily activities of a work team at a large foundry for casting heavy diesel engines, we highlight situations when the propagation, transformation, and representation of information are not supported by prescribed work processes and propose recommendations for how this can be amended. The study was conducted by several visits to the aforementioned factory with cognitive ethnography as the basis for the data collection. The focus was on identifying interruptions and analysing these through a distributed cognition framework as an initial step towards studying interruptions in a manufacturing environment. The key findings include the identification of three, previously undefined, types of interruptions and the conclusion that interruptions do indeed affect the distributed workload of the socio-technical system and thus the overall production performance at the casting line.

Coordinating the interruption of assembly workers in manufacturing

This paper examines how interruptions from information and communications technology systems affect errors and the time to complete tasks for assembly workers. Interruptions have previously been examined in laboratory experiments and office environments, but not much work has been performed in other authentic environments. This paper contains the results of an experiment that was performed in a simulated manufacturing assembly environment, which tested the effects of interruptions on a manual assembly task. The experiment used existing interruption coordination methods as a basis, and the results showed a difference in the effect of interruptions and interruption coordination between cognitively complex laboratory tasks and manual assembly tasks in an authentic environment. Most notably, the negative effects of interruptions delivered without consideration were smaller in this experiment. Based on these findings, recommendations were developed for designing interruption systems for minimizing the costs (errors and time) imposed by interruptions during assembly tasks in manufacturing.

The effect of information mobility on production quality

This article investigates the use of a hand-held unit as an information source in manual assembly. Having a mobile information system, such as a Personal Digital Assistant (PDA), that can be brought at all times, as opposed to a stationary one, such as a computer terminal, is hypothesised to increase the information range and thus improves assembly performance. The increased information range is argued to be due to assembly workers employing a cost–benefit strategy, where the cost of gathering information is compared with the assumed benefit of it. This article reports empirical data comparing the use of a mobile information carrier with a traditional stationary computer, and results show that the use of a PDA significantly improves quality, whereas productivity does not significantly improve quality.

Applying cognitive science to digital human modelling for user centred design

To build software which, at the press of a button, can tell you what cognition-related hazards there are within an environment or a task, is probably well into the future if it is possible at all. However, incorporating existing tools such as task analysis tools, interface design guidelines and information about general cognitive limitations in humans, could allow for greater evaluative options for cognitive ergonomics. The paper discusses previous approaches to the subject and suggests adding design and evaluative guiding in digital human modelling that will help a user with little or no knowledge of cognitive science to design and evaluate a human-product interaction scenario.

Incorporating Cognitive Aspects in Digital Human Modeling

To build software which, at the press of a button, can tell you what cognition related hazards there are within an environment or a task, is probably well into the future if it is possible at all. However, incorporating existing tools such as task analysis tools, interface design guidelines and information about general cognitive limitations in humans, could allow for greater evaluative options for cognitive ergonomics. The paper will discuss previous approaches on the subject and suggest adding design and evaluative guiding in DHM that will help a user with little to no knowledge of cognitive science, design and evaluate a human- product interaction scenario.

Tool use and collaborative work of dock assembly in practice

Abstract In order to deepen the understanding of the intrinsic interactions and interplay between humans, tools, and environment from a systems perspective, research in the wild (RITW) approaches have gained traction during recent decades as they provide a higher ecological validity of findings. This paper presents a RITW study, investigating how assembly, in this case dock assembly of forwarders, was done in practice. As our theoretical foundation, we used the framework of distributed cognition, which is one of the main pillars of RITW. The findings are presented in narrative form, describing and highlighting that the workers achieve an efficient production outcome by being integral parts of the whole production process and doing so through coordination of activities benefitting the shared goal of the distributed socio-technical system.

Distributed Cognition in Manufacturing : Collaborative Assembly Work

Cognitive science is becoming increasingly central within humanfactors and ergonomics (HF&E) and there has long been a call for a more systemicperspective in the area with a somewhat broader un ...

Interaction effects affecting human performance in manual assembly

This paper presents an experimental study aimed at investigating interaction effects affecting personnel in manual assembly. The main experiment with 36 subjects used a mixed method design which included a quantitative study, including time and errors as dependent measures, and a qualitative study, including workload ratings and a questionnaire. The overall task in the experiment was to assemble components on a pedal car. The main factors involved were assembly information (text & component numbers or photographs), material presentation (using structured kits, unstructured kits and material racks) and component variation (situations with and without component variation). It was found that performance, measured in assembly time, was best when combining photographs with no component variants and when using an unstructured kit.

Experimental study of cognitive aspects affecting human performance in manual assembly

Abstract This study investigate different ways of presenting material and information at workstations while using mixed assembly mode with product variants. The experimental set up annotated an assembly line involving 36 subjects. The material presentation factor involved the use of a material rack compared to using an unstructured kit as well as a structured kit. The information presentation factor involved using a text and number instruction compared to a photograph instruction, and situations with and without component variation were considered. Results show that assembly times and workload ratings were lower when using a kit, whereas using a material rack resulted in perceived decreased workflow and increased stress and frustration. Moreover, assembly times and workload ratings were lower when using photographs, whereas using text and numbers increased mental workload. The results could be useful when planning work places and production systems in order to obtain a better workflow and an increased human performance.