John Skaar

• Skaar, John; Bølviken, Trond & Kalsaas, Bo Terje (2025). Revitalizing Language Action in the Last Planner System™. Annual Conference of the International Group for Lean Construction. ISSN 2309-0979. IGLC33, p. 1266–1273. doi: 10.24928/2025/0180. Full text in Research Archive Show summary

  The Last Planner System™ has been instrumental in advancing construction through improved collaboration, reliability, and workflow planning. Building on the foundational principles of the Language-Action Perspective, this paper emphasizes the need to make critical elements of project planning more explicit, namely: the importance of saying ‘no’ and the visibility of actual work. An evolution of the Should-Can-Will-Did framework is proposed by explicitly stating Shouldn’t, Cannot, Won’t, and Did Not. Incorporating these elements in the presentation of the Last Planner System emphasizes the importance of not taking the preferred outcome for granted while creating space for genuine commitment. Representing the work itself in the system's presentation highlights the dynamic nature of execution, reinforcing the integration of planning and doing. These refinements aim to create a more transparent, resilient, and actionable framework, aligning planning efforts more closely with the complexities of project delivery.

• Bølviken, Trond; Skaar, John; Kalsaas, Bo Terje & Koskela, Lauri (2025). What Types of Problem-Solving are Used in the Last Planner System? Annual Conference of the International Group for Lean Construction. ISSN 2309-0979. IGLC33, p. 448–458. doi: 10.24928/2025/0217. Full text in Research Archive Show summary

  The paper presents the framework of Four Types of Problems, published by Art Smalley in 2018, and uses the framework to discuss how problems are solved in the Last Planner System. A problem is defined as any outcome other than the desired performance at any given time. The framework categorizes problems and problem-solving into four distinct types: Troubleshooting, Gap from Standard, Target Condition and Open-ended. The first two types are about maintaining a current standard (to reach the bar), while the two latter are about raising the standard (to raise the bar). The paper finds that Troubleshooting is in fact a dominant way of solving problems in the Last Planner System. Given that Last Planner is generally held to be a pro-active planning approach where tasks are being made ready for execution, this might seem surprising. Among other things, the reason lies in the project-based nature of construction.

• Skaar, John; Bølviken, Trond; Kalsaas, Bo Terje & Koskela, Lauri (2023). What Does a Commitment to a Plan Mean? Annual Conference of the International Group for Lean Construction. ISSN 2309-0979. 31, p. 1407–1417. doi: 10.24928/2023/0251. Full text in Research Archive Show summary

  A plan in the making should pull from what creates customer value and from the performers' knowledge and understanding of the context. A plan for commitment should represent the customer's intent in a way that calls for action on the intent's behalf. A promise to commit to a plan happens at many levels and in many forms toward execution, and every promise made becomes a push mechanism to keep that promise. Since a plan represents both push and pull around a commitment, knowledge about these mechanisms can help to understand a plan's function. The main contribution is a reflection on how a plan's push for commitment interacts with emergent situations and an analysis of what part of the commitment is within or outside the scope of the promise and the promiser's influence and control. The promise made committing to a workplan as input to a Percent Plan Complete measurement is used as a practical example. The paper's conclusion arguably strengthens many of the existing parts and principles of the Last Planner System but also gives suggestions for improvement.

• Kalsaas, Bo Terje; Bølviken, Trond & Skaar, John (2022). The Dual Nature of Complexity in Construction Management–Call for a Renewed Debate. Annual Conference of the International Group for Lean Construction. ISSN 2309-0979. p. 552–563. doi: 10.24928/2022/0160. Full text in Research Archive Show summary

  The paper is conceptual, with the aim of raising a new debate on complexity and value creation within IGLC. The topic of complexity in construction projects was first raised in the Nineties before it in the early 2000s was introduced on the Lean Construction and IGLC agenda. When facing a complex problem, there are two possible strategies to pursue with reference to the Cynefin framework for complexity. The first is to transform and move the problem into the complicated or even simple domain, thereby making it manageable. The second is to handle the problem within the complex domain. The dominant approach within both Project Management and Lean is the first, namely, to emphasize efficiency, flow, standardization, best practice, planning, reliability, and control. The paper challenges this lop-sidedness by pointing out its potential reductionism and argues that we should also appreciate, exploit, and take advantage of complexity instead of just combatting it. Value creation is reliant upon both strategies and is therefore not a question of either or, but of balance and trade-offs based on an inherent dualism.

• Skaar, John (2022). Sensemaking of Guiding Principles in Construction Projects. Annual Conference of the International Group for Lean Construction. ISSN 2309-0979. p. 772–783. doi: 10.24928/2022/0189. Full text in Research Archive Show summary

  Processes and operations can be supported, improved, or scrutinized as an active response to guiding principles that challenge the status quo. When it comes to the subject of complexity vs simplicity the principles can contradict each other, and even flow tends to work towards simplicity while value generation adds complexity. By addressing the importance of awareness of their counter effects they can be used with care and gain even larger value as a result. Done in ignorance their use might create chaos, project loss, or production failure. The sensemaking tool, Cynefin, is used together with some core principles of lean to illustrate and explain the intent of the paper. A fundamental difference in viewpoint of a project's nature is addressed since the right sensemaking of appropriate domain in Cynefin is important for the right use of lean principles. A discussion on a fundamentally different understanding of the phenomenon of projects adds to the ontological training urged by other IGLC members. This paper argues that projects are fundamentally unpredictable and hence should be more often sensed in the complex domain, rather than in the complicated or simple domain.

• Skaar, John & Kalsaas, Bo Terje (2021). The Importance of Alignment. In Alarcón, Luis F. & González, Vicente A. (Ed.), Proceedings of the 29th Annual Conference of the International Group for Lean Construction (IGLC29. Fondo Editorial (FE) de la Pontificia Universidad Católica del Perú (PUCP). ISSN 9786124802546. p. 534–541. doi: 10.24928/2021/0211. Full text in Research Archive
• Lohne, Jardar; Torp, Olav; Andersen, Bjørn Sørskot; Aslesen, Sigmund; Bygballe, Lena Elisabeth & Bølviken, Trond [Show all 22 contributors for this article] (2021). The emergence of lean construction in the Norwegian AEC industry. Construction Management and Economics. ISSN 0144-6193. doi: 10.1080/01446193.2021.1975041. Full text in Research Archive Show summary

  Lean construction has inspired the AEC industry globally over the last decades, and this manifests within a wide array of contexts. The purpose of this paper is to provide a narrative-based qualitative analysis of the emergence and impact of Lean construction on a national level, notably in the Norwegian AEC industry. The analysis is based on the concept of paradigm shift and on empirical knowledge in the form of narratives. The narratives of practitioners and researchers provide deep insights into how Lean Construction has inspired the Norwegian AEC industry and academia, respectively. The reflections indicate that the introduction of the Lean construction principles and tools in the Norwegian AEC industry has depended on promoters who have been convinced about its advantages. The role of active promoters – in particular Dr. Glenn Ballard – is underlined as key to successful introduction of Lean Construction. Key cultural features of the Norwegian AEC industry are emphasized as important success factors. Lean Construction in Norway needs to be understood as a phenomenon occurring within a setting that is generally advantageous but also following an effort carried out on several levels. Key elements that can be used within other contexts are (1) the existence of promoters, (2) cooperation between industry and academic circles, (3) a high degree of trust and (4) a predominance of bottom-up organizations within the industry with few levels of hierarchy.

• Skaar, John; Bølviken, Trond; Koskela, Lauri & Kalsaas, Bo Terje (2020). Principles as a Bridge Between Theory and Practice. Annual Conference of the International Group for Lean Construction. ISSN 2309-0979. doi: 10.24928/2020/0065. Full text in Research Archive Show summary

  Principles can carry the intent from the theory they represent. Military strategy has a long history of being presented through principles of war. In Lean Construction, principles like “flow,” “pull,” “remove waste” are used with ease. However, have they been correctly treated and understood? Supported by a literature review, we follow the use of principles through the history and the standing and character they have gained. The work is grounded in the important position of principles between theory and practice, and methodologically proceeds through philosophical conceptualisation. We recognise the guiding, dynamic, adjustable, durable, action-oriented, prescriptive and descriptive capabilities of principles, and emphasise their important capacity to facilitate abductive reasoning. We call for reflection upon the power of principles to strengthen the theoretical conceptualisation of Lean as well as upon their power to support improvement in practice.

• Skaar, John (2019). The Power of Lean Principles. Annual Conference of the International Group for Lean Construction. ISSN 2309-0979. p. 393–404. doi: 10.24928/2019/0201. Full text in Research Archive
• Kalsaas, Bo Terje; Hannås, Gøril; Frislie, Grethe & Skaar, John (2018). Transformation From Design-Bid-Build to Design-Build Contracts in Road Construction. In Gonzalez, Vicente (Eds.), Proceedings of The 26th Annual Conference of the International Group for Lean Construction. Indian Institute of Technology Madras. ISSN 9789380689296. p. 34–45. doi: 10.24928/2018/0394. Full text in Research Archive
• Kalsaas, Bo Terje; Thorstensen, Rein Terje & Skaar, John (2015). Pull vs. Push in Construction Work Informed by Last Planner. In Seppänen, Olli; Gonzales, Vicente A. & Arroyo, Paz (Ed.), Global Problems - Global Solutions. Proceedings IGLC 2015 Perth Australia. IGLC. ISSN 9780987455796. p. 103–112. Full text in Research Archive Show summary

  The Last Planner System (LPS) is widely characterized as a pull system. In this paper the authors question if this characterization is correct. The authors argue that LPS applies a combination of pull scheduling and push control at the shop floor level. Line of balance and Takt-time Planning are also discussed. There are no findings that support that these techniques applied in combination with LPS change the authors’ main conclusion. The goal of this paper is to provide a better understanding of LPS and to contribute to the discussion of pull-push. The authors agree that pull may not always be the best option. The authors argue that choosing pull, push or a combination of the principles should be based on the production dynamic in question.

• Thorstensen, Rein Terje; Kalsaas, Bo Terje; Skaar, John & Jensen, Sigmund (2013). Last planner system innovation efforts on requirements for digital management system. Annual Conference of the International Group for Lean Construction. ISSN 2309-0979. p. 669–678. Full text in Research Archive Show summary

  The plans and on-going efforts of a major Scandinavian construction company to digitalise their LPS-inspired planning processes have provided the focus in this paper. A management system designed to reduce uncertainty by ensuring that soundness criterions are met, is proposed and discussed. The proposal involves predefining “process trains” and introducing tollgates and a traffic light system to visualize the soundness status. Our conclusion is that such a system is possible and desirable provided that the user threshold is low and that the system is low-maintenance. The latter is achieved by as far as possible making it an automatic part of other, already existing processes. If successful, the system could also provide additional support for decision-making in relation to principals and engineering issues.

• Kalsaas, Bo Terje; Thorstensen, Rein Terje; Grepperud, Andreas; Hinlo, Halvard; Jensen, Sigmund & Skaar, John (2011). INTEGRATED INWARD LOGISTICS AND CONSTRUCTION WORK AND ITS IMPACT ON EFFICIENCY IN PRODUCTION. In Rooke, John & Bhargav, Dave (Ed.), Proceedings of the 19th Conference of the International Group for Lean Construction. University of Salford. ISSN 9781907842184. p. 546–556. Full text in Research Archive Show summary

  We address a main contractor’s implementation of organising logistics, as part of the contractor’s transition to lean construction. Our research question is ‘How to identify improvements in production, on the basis of different external logistics and material flows?’ Engineering logic is applied in the paper, which builds on data from a case study. We discuss how to measure changes in production workflow efficiency, and relate this discussion to different external logistics arrangements. We only partially succeed at answering our research question in this paper, but useful experience for increasing the reliability of future measurements has been gathered, and means of improving validity have been identified. We expect practitioners to find the paper useful because of our logistics focus and method for measuring impact of logistics on production. Academics are expected to find value in our conceptualisation of the relationship between external logistics and construction work.

• Kalsaas, Bo Terje; Skaar, John & Thorstensen, Rein Terje (2009). Implementation of Last Planner in a medium-sized construction site. In Cuperus, Ype & Hirota, Ercilia Hitomi (Ed.), Proceedings of the 17th Annual conference of the International group of lean construction (IGLC). IGLC. ISSN 9789574165308. p. 15–29. Full text in Research Archive

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• Skinnarland, Sol; Bølviken, Trond & Skaar, John (2024). Collaboration in production, Routledge Handbook of Collaboration in Construction. Routledge. ISSN 9781032454825. Full text in Research Archive
• Skaar, John; Trond, Bølviken; Terje, Kalsaas Bo & Lauri, Koskela (2023). What Does a Commitment to a Plan Mean? Full text in Research Archive
• Bølviken, Trond; Skaar, John & Skinnarland, Sol (2023). Komplekse utfordringer - når sentral styring og kontroll verken gir styring eller kontroll. Byggeindustrien bygg.no. Full text in Research Archive
• Skaar, John (2023). SPRINT TOWARDS A SUSTAINABLE FUTURE. Full text in Research Archive
• Skinnarland, Sol; Bølviken, Trond & Skaar, John (2023). Samarbeid er for viktig til å bli overlatt til tilfeldighetene. Byggeindustrien bygg.no. Full text in Research Archive
• Skaar, John & Amundsen, Oscar (2023). Om involverende endringsledelse. [Internet]. Podkast. Full text in Research Archive
• Skaar, John; Bølviken, Trond; Koskela, Lauri & Kalsaas, Bo Terje (2020). Principles as a Bridge Between Theory and Practice. Annual Conference of the International Group for Lean Construction. ISSN 2309-0979. doi: 10.24928/2020/0065. Full text in Research Archive
• Skaar, John (2019). The Power of Lean Principles. Full text in Research Archive
• Kalsaas, Bo Terje; Thorstensen, Rein Terje; Grepperud, Andreas; Hinlo, Halvard; Jensen, Sigmund & Skaar, John (2011). Measuring effects of logistics. Full text in Research Archive
• Kalsaas, Bo Terje; Thorstensen, Rein Terje & Skaar, John (2010). System og resultater fra utprøving av planleggingsmetoden ”Last Planner” (Lean Construction) på Havlimyra oppvekstsenter i Kristiansand kommune. Kommunal og regionaldepartementet v/ Byggkostnadsprogrammet. Full text in Research Archive

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