MBA 513 Group Assignment 1 (Team I & II) Stonehaven Inc. Case Study (names of both group members) Group 2: Yunping Yao, A20249251 Background Information Stonehaven, Inc. , headquartered near Boston, is a major manufacturer of popular brand name non-athletic shoes for adults. Most of its products are sold in the U. S. market. Mission To response to the uncertainty of shoe designs and growing uncertainty in each style, shorten the order-to-delivery lead times in the production process. Current Operating System Cutting Section |Time Consumption (min/batch) |Cycle Time | |Machine 1. Cut shoe leather |41 |Critical time for each batch’s completion| |Machine 2. Cut linings |40 | | |Machine 3. Cut insole |32 | | The cycle time for the cutting section is 41 minutes/batch for current operating system.
Capacity= 480/41=11. 71 batches=1171 pairs Kitting Section The time taken for kitting a batch is 10 minutes. Stitching Section | |Time Consumption (min/batch) |Cycle Time | |Work Group 1. Prefit |125 |Critical time for each batch’s completion| |Work Group 2. Join |100 | | |Work Group 3. Ornament |125 | |
The cycle time for the stitching section is 125 minutes/batch for current operating system. Capacity=480/125=3. 84 batches=384 pairs Steaming The steaming time for each batch is 360 minutes. Lasting Section | |Time Consumption (min/batch) |Cycle Time | |Station 1. Staple insole |70 | | |Station 2. Toe & hell seat lasts |60 | | |Station 3.
Rough sole, pound |100 |Critical time for each batch’s completion| |Station 4. Cement sole, pull last |90 | | |Station 5. Inspect, pack |30 | | The cycle time for lasting section is 100 minutes/ batch based upon current operating system. Since the conveyor has to stop 4 minutes for the Lasting department, the total task time for this department is 100+ 4=104 min per batch Capacity=480/104=4. 2 batches=462 pairs Capacity |Department |Pairs of shoes |Capacity | |Cutting |1171 |Excess capacity | |Stitching |384 |Bottleneck | |Lasting |462 |Excess capacity | Summary
Based upon the current production operating system, the total time consumption for each batch of shoes is 636 minutes or 640???. It means it takes more than a day to produce 100 pairs of shoes. This result obviously needs improvements in efficiency and effectiveness. Improvements on the Operating System Although the steaming section is the most time consumption segment, the requirement for leather treatment results it is impossible to shorten the processing time unless purchasing more innovative machines. Batch Size
Only in the stitching section there are inventories between different groups’ work. If the company still keeps each batch’s size as 100 pairs, the average work load for each worker in work group 1 now is 25 pairs, but in work group 2 is only 20 pairs which means that there will be 5 pairs of shoes as inventories from work shop 1 to work shop 2 in the stitching section. To shrink the batch size, there are also several advantages: ? Each section’s capacity is not affected: the stitching section is limited to 125 minutes. ? Reduction Influence: only to the calculation of numbers of batches. More flexibility: if the size of each batch could be reduced to 20 pairs per batch, more flexibility will be obtained to cope with the market demand uncertainty. Cutting Section: reduce the batch size from 100 pairs to 20 | |Time Consumption (min/batch) |Cycle Time | |Machine 1. Cut shoe leather |25 |Critical time for each batch’s completion| |Machine 2. Cut linings |24 | | |Machine 3.
Cut insole |19. 2 | | When we reduce the batch size from 100 to 20 pairs, the new results will be shown as follows: Cycle time=25 min Capacity=480/25=19. 2=20 batches Internal Batch Separation Rather than let each individual worker be responsible for a single independent batch of shoes, the process will be more efficient if ask all workers in the every section to work on one batch together on the same line. This improvement will speed up the time to finish each batch of products. This tactic should be used mainly in the stitching section.
Double Capacity For the lasting section, compared with station 5, all the other stations take too long time to finish their job. The idle time between the maximum time consumption station and the minimum time consumption station is 14 minutes after we shrink each batch size into 20. To make further improvements in this section, we suggest doubling all capacities from station 1 to 4. By doing so, all the time consumption in these 4 stations will be cut into half and the idle time is 6 minutes then. Add additional workstations from station 1-4 |Without new stations (min/pair) |With new stations (min/pair) | |Station 1 |14 |7 | |Station 2 |12 |6 | |Station 3 |20 |10 | |Station 4 |18 |9 | |Station 5 |6 |6 | After we add the new stations from 1 to 4, we can see that the task time is reduce by half of the original time. Therefore, the lead time for this department is reduced from 14 minutes to 4 minutes per pair, which improves the efficiency. Summary After taking all suggestions of improvements above, the total time consumption for the same 100 pairs of shoes is 531 minutes. Discussions Job Switching The case material does not provide enough information about job switching cross steps in some sections, for instance the stitching section.
In fact, rather than reducing the size of each batch, if all 9 workers could work together from work Prefit to Ornament step, the run time to finish each pair of shoes could shrink from 3. 50 minutes to 1. 17 minutes because of economic of scale. To realize this time-reduction, further information of the machines are required, for example function change time for each machine or the possibility to make this change. Additional Investments The additional investments could be categorized into two types: additional current-type machines and innovative new ones. ? Current-type Machines: to diminish the inventories between stations in the stitching section, if machines could not used multi-functionally or the switching time is too long, add up more current-type of machines to reach economic of scale might be worthy.
The result depends on the financial situation and costs. ? Innovative Machines: to speed up some processing steps, more time-saving machines could be considered, like for the steaming section. Furthermore, with the combination of more functions in one machine, the kitting section may not be needed (if it is true, 10 more minutes could be saved from this section). Automation Up-grading For the stitching section, the role of supervisor could be cancelled by more organized operating checking and delivery system. Moreover, the standardization for each set of operation should be settled in order to reduce the idle time for workers. Map of Operating System after Improvements