I am trying to make the VSM of packing seeds.
The process are the following:
Process A , where the seeds are separated into the 4 types of products and in order to know what process are needed.
There are 4 types of products to sell.
The first 2 types of products could have these sequences:
A - D- E
A - B - D - A - E
The other 2 types of products could have the following sequences:
A - B - D - A - C - E
A - C - D - E
The first 2 types of products represents 75% of sales, and that is why i was only considering to map the 2 sequences mentioned. Also, as I analized, the first 2 products are the only one that can be transformed into a pull system. So, would that be effective for eliminating muda? The most significant muda is inventory
In that case, how can i map the process? As you can see, in the 2nd sequence, the product return to the A process. Is it possible to add a fictitious process called A 2 (that would be basically the same process in the same place of work) or it does not matter to generate a loop?
In case I consider all sequences, would it be right to add another ficticious process for C? And how in the VSM can be identify the sequences?
And what about the calculation in days of the inventory in progress?
As you can see, the are reprocessing, but it is necessary in order to maximize the use of raw material
Thanks for reading and for future comments.
First: NO fictitious process. VSMap is to show as exactly as possible the actual conditions.
Second: Sequence is generally handled lineally by picture, so just put them in order. Looping the map is usually confusing. VSM is not a layout, it is a process flow.
Third: Why can only first two products be in Pull system? It looks like you have a lot of shared processes that will require some kind of supermarket? two main process flows, both end at E and start at A, with C being an optional step.
Are these large machines (like a large stamping press) or multiple machines operating in parallel (like sewing or soldering)? The question is can any operations be separated and dedicated?
Inventory is anything not being worked on - just count it and calculate against demand (takt) not capacity.
Finally please answer: why are you doing this? Reduce lead time? Better efficiency? What is your goal?
Give another try and come back!
Thanks for your answer. I really appreciate your help. Here my comments about what you wrote:
2. VSM shows a process flow, but what happen when there is a clasification that depends of the raw material that is processing. Process A is about clasifying the raw material using 3 different types of criteria. It is like the operators analize three times when they just got the raw material in their hands. If it obeys the first criteria, it goes to process B, if it does not, it is analized again with a second criteria (different from the first one) , and in that case, it goes to process C; otherwise, the last criteria is used. So when the material come back to process A, the treatment for the seeds are not the same.
3. The first two products are entire seeds, so for the other two (they are pieces of seeds) the company starts to accumulate it until they have the enough amount to complete the number of unit for exporting, so it is not what the client asks, it is what it can be offered. I was thinking about making 2 VSM, for each groups of products, being the first VSM more relevant because of the impact in the production and in the sales.
You are right, process C is optional, same with process B, both depends of the physic state of the raw material (depends of the criteria).
Why do you say that there a lot of shared process? Is it because the types of products that you can get with the four sequences? All process are shared at least for two types of products.
Use of supermarket because of the combinations that the final product has of some process sequences? Is it because is not possible to stablish a continuous flow?
I have to say that, what the client asks is one type of product. And as you can see, when the material goes to proces B, then it is necessary to go to process D.
Most of the process are manual, process D uses 3 large machines with a big batch size (compared with the other process batch sizes), while process E has a small machine. Well, i do not think process A can be separated because you do not exactly when and in what proportions of raw material you will get will go to any of the four sequences.
The other process can be dedicated and separeted .
I am also dividing process E in their operations, that is because of work method (each operation is made repeatedly until operators get a number enough to start another operation).
When you say about counting the inventory, at what moment of production would be right? Otherwise, it will always be different everytime i try to count them. I was planning to do it when the first box of the client's order is got. And why is not possible to calculate WIP with the process capacity?
I am doing this because i want to find out how efficient are now the process, if i can maybe redisign them to increase the production. Also, one of the main problems that the factory has are the inventory level, main reason for people to believe that they dont have enough space to work.
Hope to hear your comments. Thanks in advance.