Clarissa Biotto

Since Aristotle, it has repeatedly been stressed that for engaging in a meaningful discussion or debate, the discussion parties must share, besides a language, also knowledge, information, values and goals. Although the wide variety of terms, concepts and theoretical approaches in the literature, the discussion about the phenomenon of collective human actions remains fragmented. The search for the " shared understanding " is growing in construction field, as a precondition to promote collaboration and communication among stakeholders in projects using Lean principles and Building Information Modelling (BIM). Through a literature review, it is possible to find some related concepts and terms that address collective interactions in different fields, such as shared understanding, common ground, boundary objects, mediating artefacts, standardized methods and situational awareness. The purpose of this paper is to synthetize the understanding of these concepts and exemplify how they can useful to advance the understanding of collaborative decision-making in construction. The conceptual synthesis of the reviewed approaches can be used as a new theoretical background for future researches in construction, and support the practical implementation of systems, methods and tools for collaboration, such as Last Planner, BIM and Tolerance Systems.

Integration between Design and Construction is a common topic discussed in the literature in construction. The impacts of construction industry fragmentation are quite well known: poor design quality, lack of standards and constructability, suboptimal design solutions, high number of change orders, high rate of rework in design and construction, low value delivered for clients, design and construction delays and  higher project costs. In the case of construction projects in which the design stage overlaps the construction stage, the industry fragmentation increases the projects’ risks and in some cases it nullifies the gains in cost and time which come about when using the strategy of overlapping.
Although researchers tried to address the problem of industry fragmentation by implementing new tools and methods to integrate project stakeholders, for example, using Building Information Modelling (BIM), Integrated Concurrent Engineering, Big-Room, and so on, the literature is still lacking in concepts and theories about how to integrate planning and controlling of both Design and Construction stages.
The purpose of this paper is to present the use of some concepts, such as production batch and work package, in order to create a common ground among Design, Construction and Costs simulations using BIM and line of balance. The case study is a retrofit of a set of social housing  in Antrim (Northern Ireland) which aims to improve the energy efficiency of solid wall houses, at the same time as reducing the disruption for end users. The study is part of the research project entitled S-IMPLER (Solid Wall Innovative Insulation and Monitoring Processes using Lean Energy Efficient Retrofit) funded by the Innovate UK, which aims to develop a retrofit solution for social housing built with solid walls to achieve 60% reduction in monitored energy costs, with less disruption for end users, keeping quality and safety at high levels.
The use of these concepts allowed the creation of different scenarios for design solutions and production system organization which were presented in a What-if Matrix. The costs changed as a consequence of the crossing scenarios. Adding to it, the definition of production batch and work package was essential to develop the BIM models (3D, 4D and 5D), as well as the line of balance used to plan the retrofit works and measure the end users disruption.
The research findings show that the common definition of production batch and work packages between Design and Construction stages used in the retrofit study worked as a boundary object in the development of BIM models and scenarios simulations. These concepts created the basis for the integration between design and construction, especially, in projects using BIM.
The results are not limited to the context of retrofit and further research is currently undertaken by the researchers to examine its validity and applicability in different settings.

What are the differences between production system design and work structuring? And between phase scheduling and work structuring? Which lean planning tool is better suited for each one of these design processes: line of balance, takt-time planning or flowline? This paper aims to answer these questions through a comparison and deeper understanding of production design processes, as well as the potential uses of location-based tools for production planning and control in each design effort. The method used is the literature review analyses on main lean terms and tools applied for production system design. With a better comprehension of the terms and tools, it is expected that academics and lean practitioners will be able to apply lean construction in a more aware and sensible manner. The results will also support researcher's decision about the most suitable lean tool to apply in the case studies in different production design processes.

The paper aims to investigate the implementation issues and benefits of utilising the Last Planner and 4D modelling in the context of retrofit of social housing. It presents initial results of an ongoing research project carried out in Northern Ireland, which focuses on the retrofit of solid wall homes. The research project involves the proposal of a process in which BIM is used to evaluate what-if scenarios for the retrofit of social housing with a focus on reducing user's disruption throughout the construction process. Both 4D and the Last Planner are used to ensure the retrofit works with the minimum disruption. A case study on the retrofit of a set of houses was carried out, which is part of a bigger research project entitled SIMPLER. Data was collected via semi-structured interviews, participant observation in planning meetings, site visits and documental analysis. The study sheds light on a particular type of project that has not been well explored by the lean community, i.e. retrofits. It is argued that the results can be applicable to support the retrofit of a number of solid wall homes throughout the UK.

Since Aristotle, it has repeatedly been stressed that for engaging in meaningful discussion or debate, the discussion parties must share, besides a language, also knowledge, information, values and goals. What do we know today about this issue? How can that knowledge be used and advanced? The purpose of this paper is to consolidate our understanding on the many concepts that refer to preconditions for communication and collaboration in construction projects. The underlying research is conceptual by nature, and it is underpinned by a literature review. The findings show that currently there is a wide variety of terms and theoretical approaches that refer to the discussed phenomena. This situation invites for a conceptual synthesis and empirical research for its validation.

The line of balance (LOB) is widely used for projects with repetitive batches. Nevertheless, some authors in academic literature recommend the LOB for nonrepetitive areas. In the case of residential projects which have a high repetition of the same batch the LOB is a very useful tool to plan the construction. In the other hand, developing a LOB for common areas (pavements without repetitive areas and services, e.g. underground floors, leisure areas, guardhouse and mezzanine) where there is not repetitive batches is more difficulty, and this is the reason for its scarce use for common areas. Thus, major problems in the project are verified by the lack of planning and production control in common areas. This article aims to formulate guidelines for developing a LOB for common areas through a case study at a Brazilian construction company. The methodology for developing this paper includes literature review on LOB in non-repetitive areas, characterization of the company and construction sites, development of a common areas plan using LOB and other auxiliary tools, analysis of results and formulation of guidelines for the development of a LOB for common areas. The results of this study indicated that the LOB in common areas provided plan transparency to employees and engineers, improved the control of project’s total term and decreased the allocation of workers teams.