What is the best way to group the work represented by the 16 workgroups for an average demand of 360 outgoing wires per day?
The essential best way to group the work is by the use of the assembly line through the balancing of the 47 steps which are only applicable provided the times per step is known. In this case, we can be able to determine the times per step through the use of the equation 8.2: which is as follows: CT = A/R = [ (7.5 hours/day) (60 minute/hour)]
/ (306 wires/day)
= (450 minutes/day)/ (306 wires /day)
= 1.47 minutes/ wire.
| Employees | Activities | Time | Idle time |
| 1 | 1,2 | 1.1 | 0.370588 |
| 2 | 3,4 | 0.9 | 0.570588 |
| 3 | 5,6,7 | 1.4 | 0.070588 |
| 4 | 8 | 0.5 | 0.2202588 |
| 5 | 9,10,11,12 | 1.25 | 0.323588 |
| 6 | 13,14,15 | 1.147 | 0.720588 |
| 7 | 16 | 0.75 | 3.247118 |
| Total | 7.047 | 3.247118 |
In this case, it means that 7 workers will be required to perform the task of 306 outgoing wires per day. They will have a total idle time of 3.247118 minutes.
The work should also be grouped to ensure that each step is keenly given a 100% maximum attention especially those pertaining to correction of errors and missing information.
What is your line balance if peak demand is 450 wires per day?
Suppose the workday is 7.5 hour per day. Then the time for demand rate of 450 wires is as follows: CT = A/R = [(7.5 hours/day) (60 minutes/hour)
/ (450 wires/day)
= (450 minutes/day) / (450 wires/day)
= 1 minute/ wire
In this case, only 9 workers will be required to perform the task.
| employees | activities | time | Idle time |
| 1 | 1 | 0.8 | 0.2 |
| 2 | 2 | 0.3 | 0.7 |
| 3 | 3,4 | 0.9 | 0.1 |
| 4 | 5 | 1 | 0 |
| 5 | 6,7,8 | 0.9 | 0.1 |
| 6 | 9 | 1 | 0 |
| 7 | 10,11,12,13 | 1 | 0 |
| 8 | 14,15 | 0.397 | 0.603 |
| 9 | 16 | 0.75 | 0.25 |
| Total | 7.047 | 1.953 |
What is assembly line efficiency for each line balance solution?
The assembly line efficiency is given by Et/ (N*CT)
For 360 wires per day
Assembly line efficiency = 7.05/ (11*1.47) = 43.87%
For 450 wires per day
Assembly line efficiency= 7.05/ (14*1) = 50.36%
How many people are needed for the outgoing wire process using assembly line efficiency balancing methods versus the current staffing level of 11 full time equivalent employees?
For the demand of 306 wires per day if we use the groupings according to the assembly line balancing, we need 7 employees and not 11. While for the demand of 450 wires a day using the assembly line balancing, we need 9 employees and not 11. As a result of having less than 11 employees will bring about assembly line balancing and it will also lower the labour costs.
Therefore, the saved labour costs for 7 employees = 4*30,0000*1.03= $156,000
Saved labour costs for 9 employees = 2*30,000*1.03 = $78,000
How many staff members do you need for the out-going wire process if you eliminate all rework?
The rework activities are 2, 7 and 11
Analysis of the case study
As shown in this case study, if we have an average demand of employees or the peak demand or by lowering the reworks, we will require fewer working personnel than 11. The main advantage of the 7 employees is that they will save more money required to pay more employees unlike if they are 9 or 10. However, the main disadvantage is that there will be more idle time especially after the rework activities have been removed.
However, having 9 workers is the best choice, since there will be less idle time and there is also labour cost saving as compared to the 11 employees for the task.
References
Boussabaine, A. H., & Elhag, T. (1999). Applying fuzzy techniques to cash flow analysis. Construction management & economics, 17(6), 745-755.
Wulandari, D., Soseco, T., & Narmaditya, B. S. (2016). Analysis of the use of electronic money in efforts to support the less cash society. International Finance and Banking, 3(1), 1-10.