In this work, a study on the leveling of process durations in a takt planning in turnkey construction was carried out. By introducing the method of takt planning and takt control from Lean Construction into the production process, the productivity of a construction project can be increased. However, the detailed scheduling and the strict flow of the takt leads to a low flexibility in the construction process and thus to a higher vulnerability to disturbances. In practice, this often results in significant differences between the actual taktplan and the planned taktplan. In order to prevent deviations from the takt plan and to generate a stable takt planning, this work develops an approach for leveling the process in the takt planning, taking into account the vulnerability to disruptions of the finishing trades. Its aim is to develop certain criteria that take the influence and variance of the vulnerability to disruptions of the finishing trades into account and that can also be applied to takt planning so that a stable takt planning can be guaranteed.
To this end, the first step was to identify the main finishing trades and then to define the vulnerability to disruptions and divide them into categories. These categories are based on the seven types of waste from Lean Construction. A parameter was then developed for each category to represent the influence and variance of the vulnerability of the finishing trades to disruption on takt. The parameters were incorporated as random variables in the calculations of duration. Specifically, they are described by triangular distributions in order to be able to represent the variance of the vulnerability to disruptions. The random variables were then quantified for each trade based on assumptions. In the next step, the takt planning for the apartments of the fictitious dormitory was developed and presented in a takt plan.
Based on the takt schedule, the sensitivity of the takt to changes in the timing of each finishing trade was then examined using a Monte Carlo simulation and sensitivity analysis. The simulation was performed using The Risk Kit in Excel. The results of the sensitivity analysis showed that the drywall trades followed by the painting trades had the greatest impact on the takt sequence of the finishing trades. Therefore, the main focus in cycle control must be on these trades. In addition, The Monte Carlo simulation outputted the work package durations of the trades, including vulnerability to disruptions, as intermediate results. The histogram for each work package duration shows the minimum value, the expected value and the maximum value that the duration can assume due to disturbances. Overall, the takt sequence remains stable if the takt time is followed. Accordingly, the takt sequence remains stable, if the simulated maximum value of the duration of a wagon is below the takt time. Taking this criterion into account, the takt planning was again optimized concerning to stability with the help of the simulation.
«
In this work, a study on the leveling of process durations in a takt planning in turnkey construction was carried out. By introducing the method of takt planning and takt control from Lean Construction into the production process, the productivity of a construction project can be increased. However, the detailed scheduling and the strict flow of the takt leads to a low flexibility in the construction process and thus to a higher vulnerability to disturbances. In practice, this often results in s...
»