(Instructor Name)
1. Scheduling - The drum and the rope (pp. 214-217). Describe this process.
The Drum and rope system are used to ensure that scheduling of jobs happens at the same pace that the bottleneck or dominant machine in the setup can handle them. The Drum ensures that a standard pace is set for all the machines, so that the throughput of all machines is synchronized to the pace of the bottleneck. When a piece of work is completed by the bottleneck, it sends a message indicating when the work was completed, thus informing the others in the assembly line of how scheduling is likely to proceed and aligning other activities to it. The rope ensures that the pace is maintained and that the non-bottleneck machines do not work faster than the bottleneck machines. This ensures that there is no excess pile-up of inventory at any of the work stations, nor is there excess material released for work.
2. What form of layout is used in the Unico factory – product, process, fixed-position, cellular, or combination? Support your argument by referring to the Stevenson textbook (Chapter 6).
The Unico factory uses a process oriented semi-fixed layout. This is understood from the fact that the NX 10, heat-treatment machine and the milling setup are located independently. From the narrative, it is clear that some WIP material travels from the Milling machines to the NX 10, some the other way, and some directly from the milling machines to the assembly lines. Based on this it is clear that each process is run separately.
In case of a product oriented layout, the machines required for each product manufacturing would be arranged sequentially, which they are not in this case. In a fixed position layout, every machine would have a predetermined location. That is true of most of the machines in the book, but the addition of the Zmegma and the supporting machines proves that the orientation is for process rather than fixed layout, since the addition of these machines in parallel to the NX 10 enables them to form an alternate work center. The layout cannot be called cellular, since in a cellular structure, all the processes required for a product are located in a single structure usually in a circle, so that the material can be passed from one to the other for multiple processes faster.
Lesson Six Discussion - The Goal (Chapters 28-33)
1. Why does Goldratt argue that time saved at a non-bottleneck is a mirage (p. 233)? When would saving time (workers) at a non-bottleneck resource be beneficial?
A non-bottleneck is dependent on outside factors (viz. the bottleneck) to set its timetable of deliveries. Since the non-bottleneck can work efficiently when it is working at the same pace of the bottleneck, idle time after the production needs are met is acceptable. This idle time does not affect the efficiency or productivity of the entire process; hence it does not make sense to improve the efficiency of a non-bottleneck better than that of the bottleneck.
Saving workers’ time on a non-bottleneck therefore makes sense only if those workers can be temporarily utilized in improving the efficiency of the bottleneck. For example, the NX 10 and heat treatment machines require people to load and unload batches. If the non-bottleneck workers can be used there at those points of time, it saves the cost of deploying two sets of workers. However, the workers have to be available at the time the bottleneck machine requires them, and for that should be prepared to stop work on the non-bottleneck as needed. Only then does the saving of worker time on the non-bottleneck machines make economic sense.
2. Why do workers not pass along (transfer) units (e.g., products, forms, etc.) one at a time at companies (p. 238)? What are impediments to doing this?
The key impediments passing along units one a time are basically two-fold:
- If units are passed along one at a time, the setup and transfer time required to prepare for a the next unit and ship the earlier unit to the next processing center increases, that is the queuing and waiting time becomes inordinately high. Therefore, since the purpose is to make economical use of a set-up, that is, use the existing set-up the maximum number of times before it has to be changed, units are processed in batches. This also ensures a uniform quality for the batches.
- Transportation time and cost increases inordinately if units are transferred one at a time. This is possible in case of a cellular structure or an assembly line where the system is geared to handle the product one at a time, but in other situations, it is more economical to process the material in batches to distribute the time of setup and transportation, i.e. idle time to a minimum by spreading it across the maximum number of units economically possible.
Lesson Seven Discussion - The Goal (Chapters 34-36)
- How to manage the division (pp. 282-287 and 296-297)--how should Alex manage the division?
The best way to manage the division is to improve the throughput. By traditional methods, the key measurable element being tracked was operating expenses, followed by throughput and third inventory. By changing the order around and focusing first on throughput, then inventory and finally on expenses, the division’s efficiency and output can be improved to a profitable level. By tracking throughput at the end of the production, that is the cumulative throughput of the process than at the individual level, the efficiency of Alex’s plant improved. This same principle needs to be applied at the division level. The four key steps to achieving profits are therefore;
- Find the bottleneck in the entire chain
- Decide how to exploit the bottleneck
- Subordinate everything to that decision
- Elevate the system’s bottlenecks.
- If in a previous step, a bottleneck has broken, go back to the previous step.
This process defines the Theory of Constraints. By revising the processes, new capacities can be found, leading to more opportunity for production and therefore more profitability.
- Did the plant culture change (pp. 298)? If so, how? Have you ever worked at a company with a similar culture change? If so, describe that change.
The plant culture did change, and the change was essentially one of thinking and approach. Instead of resolving each problem as a stand-alone one and creating local efficiencies, the team worked on improving the situation by identifying constraints throughout the plant, and then working towards arriving at a solution that would improve the entire proves, not just the local constraint. By developing a process of identifying the problem and then seeking answers to it beyond the immediate issues, the team was able to change the culture of the plant rom managing on contingency basis to planning for the overall efficiency and productivity.
I have worked in an organization with this kind of cultural change taking place. Initially, the focus was always on getting the best profitability of a particular order, and the sales team worked on getting the best margins on each deal. However, this resulted in a success ratio of only 10 per cent. A new change came in when we began to focus on retaining customers for the long term. We were able to get more orders by offering price discounts in exchange for larger committed orders over a longer period of time.
Lesson Eight Discussion - The Goal (Chapters 37-40)
- Problems at the plant – does the plant have too many orders (pp. 320-326)? Explain why or why not.
The plant does not have too many orders. The problem is not with the amount of the orders. The problem is with the scheduling capacity. When there are more number of orders on the non-bottlenecks, it increases the capacity utilization of these machines. This creates a problem because in the meanwhile the consumption of material at the bottlenecks results in stock-outs and the bottlenecks remaining idle. Since the non-bottlenecks do not have spare capacity, they are not able to rebuild the inventory in front of the bottlenecks, and repeated incidents result in the bottlenecks running out of material to use. By ensuring that the plant does not run to full capacity all the time, this issue can be resolved easily.
- How did Rogo and Julie try to find the balance in their home and work lives? How do you achieve this balance?
Rogo and Julie realized that due to the increasing pressures of work, Rogo had started to work more at the office. He thought that this was understood and did not feel the need to communicate it to Julie. In turn, Julie felt Rogo was spending more time at the office to get away from her. This lack of communication was the essential problem between them. By deciding to communicate more, by coming together at the end of the day just to share how their respective days had been, they were able to connect and communicate better and rekindle their relationship. A similar approach is needed for all of us. Unless we are transparent to others in our lives about what is going on, others will interpret our behavior according to their understanding and this creates misunderstanding. So, a clear communication and transparency is required to maintain and build balance in the relationship. This helps everyone understand what the other person wants and needs and adjust accordingly.
