Buffer-driven production strategies represent an effective mechanism to shield the production system performance from the ill-effects of variability. In construction, these production strategies have been an emerging issue among lean construction researchers and practitioners alike. However, there is still room to better understand the relationship between performance and buffers in construction, in order to develop suitable buffer management approaches in projects. In this exploratory research, the relationship between productivity and buffer levels in repetitive projects is investigated by using Discrete-Event Simulation (DES) modelling. Also, a specific kind of inventory buffer is studied: work-in-process (WIP). A number of simulation scenarios with varying production parameters such as production amount, production rate, variability levels and initial WIP buffer size were tested. Results show that even though WIP buffer may not contribute to improving productivity rates, but they provide very good protection to productivity levels in case of variability conditions in projects. This effect makes WIP buffer suitable for use in large scale repetitive projects where a small disruption in production can lead to heavy losses. Also mathematical relationships between productivity and WIP buffer were analyzed, finding some good nonlinear relationships able to explain to a certain extent the impact of the WIP buffers sizes on productivity.
Buffer, Discrete-Event Simulation, Productivity, Repetitive Projects, Variability, Work-In-Process.
Gupta, A. , Gonzalez, V. & Miller, G. 2012, 'Understanding the Relationship Between Productivity and Buffers in Construction: A Simulation-Based Case' In:, Tommelein, I.D. & Pasquire, C.L., 20th Annual Conference of the International Group for Lean Construction. San Diego, USA, 18-20 Jul 2012.