No abstract

No abstract

No abstract

A lean‐agile model of homebuilders’ production systems is proposed in this research. Value stream mapping is utilized to clarify the proposed lean‐agile model, in which pull and Kanban are used to ensure smooth production upstream of the de‐coupling point, while fluctuating market demands in terms of variety of homes and variability of volumes are managed by the agile process downstream of the de‐coupling point. The de‐coupling point is used to provide components to downstream agile process and shield upstream smooth production from market fluctuations. A simulation model is developed to evaluate and validate the effectiveness of the proposed lean‐agile model. Simulation experiments show that the lean‐agile model prevents the accumulation of high inventory levels and thus provides better customization opportunities for clients compared to even‐flow‐construction. It also provides a more stable process with shorter cycle times compared to sales‐driven production. The proposed lean‐agile model offers new possibilities for homebuilders to manage the balance between meeting fluctuating market demands and stabilizing the production system.Agile, housing construction, lean, simulation,

No abstract

No abstract

Construction contractors play a vital role in reducing the environmental impacts during the construction phase. To mitigate these impacts, contractors need to develop environmentally friendly plans that have optimal equipment, materials and labour configurations. However, construction plans with optimal environment may negatively affect the project cost and duration, resulting in dilemma for contractors on adopting low impacts plans. Moreover, the enumeration method that is usually used needs to assess and compare the performances of a great deal of scenarios, which seems to be time consuming for complicated projects with numerous scenarios. This study therefore developed an integrated method to efficiently provide contractors with plans having optimal environment-cost-time performances. Discrete-event simulation (DES) and particle swarm optimisation algorithms (PSO) are integrated through an iterative loop, which remarkably reduces the efforts on optimal scenarios searching. In the integrated method, the simulation module can model the construction equipment and materials consumption; the assessment module can evaluate multi-objective performances; and the optimisation module fast converges on optimal solutions. A prototype is developed and implemented in a hotel building construction. Results show that the proposed method greatly reduced the times of simulation compared with enumeration method. It provides the contractor with a trade-off solution that can average reduce 26.9% of environmental impact, 19.7% of construction cost, and 10.2% of project duration. The method provides contractors with an efficient and practical decision support tool for environmentally friendly planning.

No abstract