Cognitive assistance systems help people with learning disabilities to increase their skills and consequently their employment opportunities in the regular labour market. Research on advanced work instructions has encouraged training disabled workers in cognitively demanding production tasks, especially manual assembly. However, studies lack evidence on the effect of repetition or work cycle alongside the form of instruction and type of disability. This paper addresses this gap and reports on an experiment conducted at a sheltered workplace. Four forms of instruction (paper-based, animations, projection, adaptive projection) were tested to assist operators with three types of disability (illiterate, psychosocial, cognitive) with a manual assembly task. The results show that projection enhances the first assembly cycle. Challenging operators by filtering the content of the instruction with increased experience leads to greater independence and a better understanding of their tasks. However, adaptive instructions can form a barrier for those operators who are most dependent on mentor support. The form of instruction should thus be considered carefully for each operator as their adaptation to changes and cognitive assistance systems varies. The results are discussed in light of the Industry 5.0 human-centric and socially sustainable production agenda with managerial and research implications and future research priorities.

In variable manual assembly production of highly customised products, effective allocation of workers to products is required. To support decision-making here, industrial managers should be aware of the performance effects of the number of workers and learning within individual products. Evidence on such fundamental effects requires laboratory studies with products similar to those in real assembly industries. Because of the lack of such studies, this paper studies experimentally the effects of group size (one to four workers) and learning (up to four repetitions per group) on the performance of product assembly. The product, built for the purpose of the present study, consists of representative elements from real products in the mechanical engineering industry. A total of 68 undergraduate students participated in the experiments. The results from the experiments are in line with the hypotheses that the mean assembly time decreases at a decelerating rate as a function of both group size and repetitions, and that productivity per worker decreases as a function of group size. The results are explained in more detail through the experiences of the participants. Managerial implications and aspects for future research are also discussed.

With growing emphasis on sustainability, companies are shifting from prioritizing cheap labor and high production volumes to focusing on sustainable manufacturing and localized supply chains. This study examines how the sourcing location decision of a Finnish manufacturer affects the carbon footprint of an iron sand-cast component. A questionnaire was used to collect data on material (new and recycled metals and sand) and energy (electricity and heating) consumption for the annual production of real components from foundries in Finland, Germany, the Czech Republic, and China. The consumption data, or activity data, were multiplied by their respective emission factors to calculate CO ₂ -equivalent emissions per kilogram of the component. Domestic sourcing in Finland produced the lowest emissions, while sourcing in China triples the emissions when including transportation and is more than double when excluding transportation. This highlights significant regional disparities in pig iron and energy usage. The foundry emissions in Finland and Germany were, on average, the same, as heating in the former compensated for the higher electricity emissions in the latter. These findings encourage manufacturers to focus not only on distance but also on the resource consumption of their suppliers. Graphical Abstract