The study of the current production line We categorised the process into five stations (i.e., weighing and mixing, pasteurization and homogenization, filling and packing, packing in big
bags and storage) as shown in Figure 2. We collected the current cycle time for each workstation for 30 replications from all employees in the stations and calculated average cycle time of all stations.
Identifying the bottleneck operation and calculating takt time The bottleneck of the pasteurized milk process was filling and packing in station three. We computed the takt time according to Equation (1). The total customer requirement was 8269 litres per day. The production capacity is the production time of eight hours per day including a one-hour break, which plans to produce 86% of all production quantities. Thus,
T = (8 h/day – 1 h/day)*(0.86*3,600 sec/h)/82,691 l/day = 2.62 sec/l
With a machine breakdown allowance of 5%, we can calculate the adjusted takt time as follows: TA = 2.62*0.95 = 2.49 sec/l Calculating the standard time of the production line We collected the cycle time for each station and determined the number of replications of cycle time at a 95% confidence interval. The maximum number of replications was less than 30. Hence, our data collection was sufficient to calculate. We defined the personal allowance to 3%, basic fatigue allowance to 2% and delay or contingency allowance to 5%. Thus, the total allowance is 10%. Then, we calculated the average cycle time, normal time, standard time and cycle time per worker for 1 litre of pasteurized milk as shown in Table 1.
E = (100*4.95)/(5*1.51) = 65.51%
From the analysis, the cycle time per worker of