The following chapter provides an overview of alterations planned by the manager of the company. We listed some changes that are not compatible in the lean manufacturing objectives and made suggestions to improve the results of the company. 2) Current situation Doing the analysis of the changes that the manager considers to make in the company, it’s important to say that the first thing to do in the just in time is not to produce while the customer does not request the respective product.
By the principle of the Kanata pull system, the worker only has permission o produce when a pull signal is sent to him, normally manifested through a card or an empty container, What we can see at the manager changes is that she wants to store a buffer of at least two days in front at the workstation, in order to try the worker to produce faster. In fact, this is bad for the company because that inventory its not giving profit for the company. Another important consideration to make it’s about hiring three workers to inspect the products after the production. The quality at the source is an important factor in the lean manufacturing.
It refers to the theory Of employees assuming the responsibility for the quality of their own work, they are expected to make a part of the final product correctly at the first time. Finally, it s kick like the manager have not seen that keeping the skids filled because of the high utilization of the machines and labor will provide a bad flow through the production line. Although her good intentions for the company, providing this change, probably the production will not attend the demand and it will result in fines and, worse, the company probable will lose that client. ) Methodology In order to change the reality of this company, notably characterized by high level to inventory, several qualify problems and steady profit: a different approach should be utilized, The main technique that will he applied to reach this goal is the Lean Manufacturing. The Lean manufacturing approach is based on eliminating as most waste as possible and one of the major causes for waste in a factory is certainly inventory, including in Quality Parts Company. However, SIT has been successfully applied Kanata to control inventory level.
However to make more efficient recommendations, our analysis will not be limited to this approach. Therefore, other methods like Theory of Constraints, job sequencing, line balancing will be used. The Theory of Constraints is a way to find a control point to manage the flow of product through the system. Finding the constraint of the production line will allow time saving. It’s important to focus the analyses on this resource because it strikes the beat Of the entire production.
In order to understand how many workstations will be needed and consequently how many workers (assuming one worker for each workstation), the line Will be balanced. Here the expectation is to reduce costs reducing the number of workers. The purpose is to assign all tasks to a series Of workstations in a way that prevent each workstation of having a bigger operation time than the cycle time. This will minimize the unassigned time across all workstations. One of the major difficulties is to respect the precedent relationship inherent of the assembly line itself.
The job sequencing will be utilized to minimize flow time. This is one of the standard measures of schedule performance used to evaluate priority rules, With this choice of priority the most adequate rule is SOT (shortest operation time) cause it is the one who minimize the MET (mean flow time), less important to state that the due dates weren’t given which means that the option could have been another one. 4) Recommendations 4. 1) Layout The first area that this methodology is going to be applied is the factory layout.
As can easily be seen, the entire layout of the plant is contributing to elevate the waste, mainly by the unnecessary movements between operations, besides it, the large distance among the machines requires larger batch sizes. The design below brings a substantial improvement: Figure Layout proposed In this new layout we opted to adopt two U shaped manufacturing cells. The first one is composed by the lathe, mill and both drills. And the other line by the paint, oven and packing. This change allow us to reduce the number of employees from 13 (one of them a worker) to 10 operators.
The reason to achieve this improvement was that in the new layout several operators are doing more than one job: operator 2 works on the mill and the drill, operator 8 works painting and packing, operator 7 inspects before the assembly and also brings parts trot the subassembly, finally, operator 10 inspects before the lathe ND feed the mill and the lathe, 4. 2) Line Balancing The allocation of workers given above was done using line balancing and the benefits of the U shaped line.
To achieve the best result the first thing done was to find the ideal cycle time in the worst scenario case. The demand for the three products is 175 units per month and assuming that the factory works in one shift Of 8 hours and five day in a week, the ideal cycle time (C) found using the formula bellow’s approximately 54,86 minutes. With this cycle time and only using the balancing approach without a U shaped nine, the result found is of one worker in each operation, given the total of 12 operators (remembering that we added one more inspection) more one worker to feed the machines.
However, as can easily be seen in the layout above and with the table below, operator 2 have all conditions of work on drill and the milling. Operation Operation time(minutes) Remaining unassigned time(minutes) Station Milling 3486 Lathe Drill 1 39,86 Driers 1486 Assembly I Assembly 2 Assembly 3 Inspection 24,86 Paint Oven Table : Line balancing approach The final allocation of workers optimized with the U shaped line used is given low: Worker Tasks Drill I and mill Drill 2 Inspection 2 and supply subassembly products Paint and packing Inspection I and supply raw materials Table : Final allocation of workers 4. ) Kanata Production Control Systems A khan system is responsible for control these buffers and works in a simple way: an employee withdraws material to work on it; this material is stored in boxes of four products. At the same time the operator puts the Kanata card, which was in the box, in the Kanata board. The employee of the previous operation checks the Kanata board and if there is any Kanata there he is allowed o produce in order to replace these 4 units.
