Problem with creating VSM current map

[Pruuu]

Hello,
I've just started my adventure with Lean. At this moment I am on my student internship in company which produces shock absorbs. My main duty is to conduct VSM of one family of the product, and I should admit I've got stuck and nobody in company is willing to help me. I will present my situation: I know the process, described the flow, but problem showed when i was gathering process indicators and inventory/stock and buffer.
The company has two production areas:
1 - small unit where are produced rods as main component of absorbs
2 - big unit - assembly lines - where the rods from small unit is transported and converted with other purchased components in final product.

The first problem is concerning assembly lines, main product contains the 1 rod, and 4 other components. I've got indicators of 4 purchased things like c/t, c/o uptime etc., but I do not any of whole Rods area, it means indicators of each process are available and I have them, but I am not sure how to count c/t of the whole units.
In the rod area we have some processes like:
- cutting c/t = 6s
- lathing c/t = 13,36 s
- grinding c/t = 5 s
- plating c/t = 3,66 s
- polishing: 1st machine c/t=7,51 s, 2nd machine = 5,40 s
3x shifts, 1 operator per shift

In my opinion c/t of Rod area should be ~34 sec, as adding each process c/t.? but I am not sure. If you have any ideas, please write how to count c/t of Rods area.

2) Second problem is related with inventories, stocks, Vips. In your opinion, is it possible to create a good VSM if I use the data about inventory purchased and in progress from SAP? It is really hard to find out how many components are left between workstations, because company produces a lot of different final products, people from the production have a problem to say how many they have.

Thanks for any answer, sorry for mistakes in the post. English isn't my national language.

 

[Stijloor]

A Quick Bump!

Can someone help?

Thank you very much!!

 

[RosieA]

Pruuu, You summary doesn't mention it, but did you start out with an ABC analysis of the end product? It sounds like you're looking at all your products instead of the high runners. All the products is too big a chunk to work on, and will introducre variables that are distracting.

Start by looking at the A and AA items that go through the line, and work up your metrics on those products. I think you'll find that sub-set easier to work with.

 

[wmarhel]

Pruuu,

The first step to any value stream mapping process should be the product family matrix. Without doing this, and far too many companies I come across don't, you allow for a lot of variation and noise into the system.

The purpose of a product family matrix is to first identify those products that share similar processing steps and the sequence of those steps, looking for groups that can be developed. Step two is to take that general matrix and then apply the individual process times to see if it breaks down further by looking for products with 80% similarity.

A key point is that the product family matrix for VSM, is not necessarily going to be same as the product families that an engineering or purchasing might use: fasteners, castings, etc.

Stay away from SAP or any other MRP/ERP system. Pulling data out of the system isn't the point of VSM. Have the person at the work cell take an educated guess if need be. It probably isn't going to be that far off, and probably going to be closer than what is in the ERP.

Wayne