Currently, no appropriate standard exists that describes how to determine the in-plane shear stiffness for cross-laminated timber (CLT) panels, meaning that, there is a lack of appropriate and reliable test methods. In this paper, two gross shear test methods are evaluated: a picture frame test and a diagonal compression test, which are intended to measure the shear stiffness of a whole CLT panel. This evaluation aimed to compare the shear modulus, the amount of compression/tension in the diagonal directions of the panels and the deformations of both sides of the panels. The picture frame test and diagonal compression test provides a bi- and uniaxial pre-stress, respectively. A total of 30 non-edge glued CLT panels were tested, 17 3-layer and 13 5-layer panels. The shear modulus for the 3- and 5-layer non-edge-glued panels were measured as 418 and 466 MPa, respectively, in the picture frame test. In the diagonal compression test, the shear modulus was measured to substantially higher values of 530 and 626 MPa for the 3- and 5-layer panels, respectively. In the picture frame test, panels were equally stretched along one of the diagonals as they were compressed along the other diagonal, which was not the case for panels in the diagonal compression test. The test results also showed that measuring only one side incurs a risk of over- or under-estimating the in-plane shear modulus. Compared with results from the literature, the picture frame test seems to be a more reliable test method than the diagonal compression test.

The majority of companies involved in value delivery in the Swedish housing industry are Small- and Medium-sized Enterprises (SME). An SME is often managed in an informal way with focus on sales and production. Many SME are also financially vulnerable as they are strongly dependent on a few key customers and key products. As variation will always exist, SME should learn to deal with variation instead of try eliminating it. This paper hypothesises that structural flexibility in SME supply chains through horizontal collaboration leads to a regional environment of economical growth from which all active SME will benefit. The hypothesis is examined through two case studies; a Swedish supplier network that has worked together six years and a four year old Norwegian supplier network. A benefit of collaboration is knowledge sharing that lessens the economical strain of keeping up with the “latest”. Other examples of collaboration are shared production resources in case of low capacity. Collaboration within supplier tier networks is considered to mark the emergence of a “collective strength” that improves individual suppliers bargaining position towards their customers. This evolution is considered an indication of the emergence of a “Lean Enterprise” within the house building sector.

Research Question/Hypothesis: Value Stream Mapping (VSM) can, independent of work repetition, improve the performance of civil engineering projects by allowing the site management to visualize the flows of materials, resources and information.Purpose: The purpose is to show how VSM can be used by on-site practitioners to see the day-to-day flow of work, to understand the effect of straight-forward improvements to workflow, and to see the effect of applying industrialized working methods.Research Method: Applicability of VSM to civil engineering is examined through the fixing of reinforcement in two bridge construction projects. A traditional bridge was used to map (current state) and improve (future state) workflow. The potential of modern production methods are then analyzed in a second bridge project (ideal state).Findings: Allowing the site management to visualize and to see workflow improves the work performance of the two studied bridges. Addition of easy to understand and calculable metrics for lead time, inventory level and manufacturing costs, emphasize the potential savings of reactive and proactive workflow measures (≈ 80-90 %).Limitations: The paper considers fixing of reinforcement in two bridge construction projects. Additionally, the so-called future state bridge was not actually constructed, i.e. the savings stated for the future state, even if reasonable, are an approximation.Implications: The framework to visualize current, future and ideal workflow provides a framework to extend the VSM methodology to civil engineering projects.Value for practitioners: To overcome the sub-optimized mindset in civil engineering that repeatedly leads to the same practice, the paper proposes a straightforward and easy to use framework to visualize and analyze effects of workflow improvements.

Industrialised house-building suppliers must learn to see how the lack of resource management disrupt the synchronisation of their production processes both upstream (e.g. capability to forecast material consumption) and downstream (e.g. order delivery Just-in-Time). In contrast to focus on workflow as is more common in construction, Systematic Production Analysis (SPA) is a tool capable of providing a more robust production process in terms of better resource characterisation and predictability. A roadmap model, composed of six steps, has been developed for simple introduction of SPA. The model is a straightforward way of classifying the production system in terms of impacting resource and parameters attributing to production loss (scrap or downtime). The applicability of SPA is analysed through a pilot case study at a patio door manufacturer. Two main response parameters emerged related to scrap; surface and dimension errors of the work piece material (wood). An objective function was formulated to reduce the scrap without increasing the total cost of the work piece material. It was suggested that the case company evaluates Engineering Wood Products (EWP) leading to a more robust production process (less scrap), but in turn increasing the initial cost of the work piece material. Other potential measures are purchasing new processing tools, investing in new machinery or educating workers which all, directly or indirectly, lead to reduced scrap. Consequently, proper management of production resources will improve their predictability and in turn improve production control.

An SME is often managed in an informal way with focus on sales and production. Many SME are also financially vulnerable as they are strongly dependent on a few key customers and key products. As variation will always exist, SME should learn to deal with variation instead of try eliminating it. This paper hypothesises that structural flexibility in SME supply chains through horizontal collaboration leads to a regional environment of economical growth from which all active SME will benefit The hypothesis is examined through two case studies; a Swedish supplier network that has worked together six year and a freshly started Norwegian supplier network. The Swedish suppliers are cooperating; e.g. in case of low capacity, they are sharing production resources. Another benefit of cooperation, supported by Norwegian findings, is the sharing of knowledge amongst each other that lessens the economical strain of keeping up with the “latest”. Cooperation within supplier tier networks marks the emergence of a “collective strength” improving individual suppliers bargaining position towards their customers, e.g. when obtaining new orders, when lobbying for changes in regulations, or when developing and verifying new products. This evolution indicates the emergence of a “Lean Enterprise” within the house building sector.

To improve, it’s crucial to see! Vital characteristics of Lean are visualisation and transparency, i.e. allowing everyone to see all what occurs in production. A common tool for this purpose is Value Stream Mapping (VSM). Due to varying flows, performing a successful VSM in construction confers additional challenges. In this paper, lessons learned from successful VSM studies in construction are provided.Three VSM case studies were performed at different companies ranging from patio door manufacturing to kitchen cabinet assembly. Lessons learned can be structured into three phases; preparing the VSM (selecting “value stream leaders” and VSM team, clarifying values, etc.), performing the VSM (use of mapping tools, approximation of key indicators, waste identification, etc.), and following-up the VSM (Plan-Do-Check-Act, evaluating customer values, etc.).For the involved companies, the lessons learned imply the start of a “Lean journey” even though the involved companies found it difficult to relate VSM improvements to business strategies. Consequently, there are opportunities to further improve the application of VSM. However, it’s important to remember that VSM is about the straight-forward visualisation of flows and that these flows are made transparent for the whole organisation.

Purpose – The purpose of this paper is to hypothesize that value-driven purchasing of customized kitchen cabinets is more profitable than market-driven purchasing in industrialised housing construction. The hypothesis is examined through a case study of kitchen carpentry at one of the Sweden's largest producers of industrialised prefabricated multi-storey housing. By comparing characteristics of market- vs value-driven purchasing, this paper aims to further clarify the benefits and drawbacks of these two strategies. Design/methodology/approach – By comparing characteristics of market- vs value-driven purchasing, a theoretical framework is proposed that clarifies the benefits and drawbacks of the two strategies. An explorative case study of kitchen carpentry at a house manufacturer illustrates purchasing of kitchen cabinets in the industrialised housing industry in relation to the proposed framework. Findings – The case study results indicate that, from a value perspective, a long-term relationship with a dedicated local smaller supplier is a preferable choice over a short-term relationship with a low-price mass producer. Research limitations/implications – This is a single case study that should be verified by further empirical work of a test delivery from the local sub-system manufacturer. Such a study would provide more insights into this area of work and make it possible to thoroughly evaluate potential risks. The indicative results in this paper can be made conclusive through quantification of the proposed lean purchasing characteristics. Originality/value – A comparison of value- and market-driven purchasing is carried out in theory and applied to a real case study that brings new perspectives to purchasing. In this way, the paper proposes alternative purchasing strategies to the construction industry

Projektet syftar till att arbeta fram en modell för hur modularisering kan utnyttjas praktiskt i byggsammanhang. Specifikt handlar det om att definiera och avgränsa moduler samt att redogöra för hur en teknisk plattform kan skapas som stöds av en individuell utveckling av moduler för tekniska installationer. Medverkande parter Universitet: Luleå tekniska universitet (LTU) Företag: Lindbäcks Bygg AB Norvag Byggsystem AB Moelven ByggModul AB Setra Group AB Martinsons Byggsystem AB