Lean construction – nuläget / Lean construction – the current situation

Rapport, 2023

Lean construction (LC) has been discussed by Swedish contractors since ca. 2007. Those 16 years up to 2022-2023 also saw an increasing Swedish research interest on LC. Hundreds of relevant publications and dozens of BSc, MSc, Licentiate, and PhD theses have been produced over the years. This seems to show that the discussion on whether LC can help in tackling issues in Swedish construction, has remained vibrant – both regarding long-standing challenges (e.g., productivity, efficiency, value creation), as well as emergent ones (e.g., climate goals, unstable markets, inflation).

However, limited studies on the sector-level LC practice have been offered so far. Studies featuring empirical cases do exist but are few compared to the total number of relevant publications, and the empirical material itself mostly clusters around a few specific companies pioneering LC in Sweden. Moreover, industrialized construction tended to be very visible in many research and practical efforts, to a degree disproportionate to its market share. Swedish construction is still dominated by on-site production, even if there is a well-embedded practice of using prefabricated components and other specific off-site elements. As such, this project sets out to clarify the current Swedish LC state-of-art, by investigating how well the relevant research output reflects Swedish practice in 2022-2023, and empirically surveying the actual state to which LC is currently found within the Swedish construction sector. In doing so, it also identifies the variants in which LC is practically implemented in Sweden – as identifying LC practice variants in a national context can facilitate LC adoption in a way that fits actual industry needs, provided that national institutional influences on LC practices are acknowledged.

Methodologically, the study comprises a systematic literature review of Swedish LC research featuring empirical content (even if narrow), followed by a nation- and sector-wide questionnaire survey targeting all construction-related firms (excl. industrialized house builders) across all geographical regions in Sweden. The companies were asked about what, when, and how much they are doing with LC in their practice. The results following the analysis of the literature review and the survey response data, were qualitatively synthesized using abduction. The reviewed studies were analyzed in terms of their themes (industrialized construction or conventional construction), process coverage (design, production, partnering and stakeholder collaboration, planning, strategy, supply chain), paradigms (systems theory, business economics, organizational behavior, interpretivism), and content. Through this analysis, the preliminary variants of LC: Industrialized construction, production processes, production strategy, design, planning, and logistics and supply chain, were derived – indicating that Swedish LC practices primarily focus on improving technical process parameters. Moreover, the studies featuring empirical content were few compared to the total number of Swedish LC-related publications, and that content itself mostly clustered around a few specific companies pioneering LC in Sweden – indicating a lack of a sector-level understanding of the actual LC state-of-art. Finally, as mentioned before, industrialized construction monopolized the interest of many research efforts – disproportionately to its market share.

Those problematizations deriving from the literature review served as the background of the nation- and sector-wide questionnaire survey conducted from August 2021 to January 2022. Targeting 1342 companies, it received 471 valid responses, thus having a 35% response rate. The survey showed that there is a large discrepancy of LC knowledge and practices across Sweden. In certain cases, the survey respondents indicated through their answers a well-adapted implementation of LC. However, 286 out of 471 respondents (i.e., 61% of the total responses!) claimed to not even know what LC is. Nonetheless, a sub-group of the surveyed companies claiming to be unaware of LC, still went on to answer to the survey in a way indicating that, in fact, they did know about LC. In other results, while there have been some precise cases of undertaking communication, training, and other auxiliary activities (e.g., simulation), most responses exhibited a not particularly detailed application. Furthermore, previous and present states of LC implementation were mostly piecemeal – certain LC elements, like waste elimination and customer value increase, have been comparably applied in the past and now, but others, like Last Planner, have gone through phases of varied application. The analysis of the responses of companies that have been implementing LC, shows four practical LC variants: (1) a variant related to IT-supported design, (2) a production variant, (3) a planning variant using Last Planner, and (4) a supply chain and logistics variant focused on partnerships with suppliers. Compared to the preliminary variants found in the literature review, the variants found in Swedish LC practice through the survey are fewer (four instead of six), more narrowly defined, and more simplified – indicating that, in practice, only specific LC elements have been more popular (e.g., Last Planner). The survey has shown that lean construction has been implemented by both large contractors and SMEs (e.g., subcontractors, HVAC installers) which claim to be LC-competent. Moreover, the emergent practical LC variants show that the Swedish adoption of LC (when it happens in the first place) follows patterns apparent in the adoption of many other management concepts – i.e., picking parts of the full concept and shaping it to local needs, thus giving the adoption different scopes in the building processes and firms. This might mean that each variant could be further customized to fit the business activities, business model, corporate culture, organizational structure, and even local peculiarities of a specific company. As such, while those variants can be disseminated to interested parties via communication and training activities, it is highly probable that each party will then take the variant that applies most to them, and further contextualize it to completely fit their case.

This is the first Swedish research study investigating the LC state-of-art on such a scale. It provides empirical evidence of a Swedish state-of-art that cannot be found in previous, narrower studies. It also shows that the diversified implementation of LC in Sweden departs from a more “purist” understanding of LC. As such, LC research, training, information, and dissemination, might need redirection to realistically meet industry demands. In parallel, LC practice should possibly be informed by a combination of top-down and bottom-up strategizing. Finally, a stronger crossindustry collaboration may be needed for facilitating LC knowledge and practice in Sweden.

Future work can include the continuation of the present study into shaping the way forward for practical LC implementation in Sweden – as issues claimed to have been solved by LC (e.g., high production costs), are still apparent. This could mean that besides processes, the effect of LC on organizational needs, culture, value streams, development, growth, and human interaction, should be further investigated. This can include the enrichment of the identified variants with more relevant concepts, processes and tools able to help attaining industry and company demands, the incorporation of those enriched variants in the portfolios and strategy of organizations advocating for the use of LC, and, crucially, considering the integration of sustainability and circularity with LC, through a stronger focus on processes like end-of-life disassembly instead of demolition, and production oriented to recycling and reusing.