The recipe works weird. First it says 1 wood gives 1.5 seedlings. Why that half? Secondly it produces different number of Seedlings each time.. I have run into problems of unstable production chain and reproduces the issue on the new map by only building an assembling machine. I give it 10x wood and 13 Seedlings are produced. Then I give it another 10x wood and 18 Seedlings are produced.

Is that how it should work?

Are you using Bob's greenhouse by any chance? Bio Industries should produce seedlings and woodpulp. And at a fixed quality. Bob produces seedlings and wood.

I am talking about producing seedlings in an assembly machine not in bio industry. I am using this in an early stage as an input for producing basic wood in this big greenhouse.

Here are some screenshots if that would be helpful to solve the bug or just to clarify what I am doing wrong: http://imgur.com/a/ctorz

The first one shows the recipe I am choosing in Assembling Machine (the smaller blue one)
The second one shows the recipe I am choosing in the Bio-Farm
The last two shows a run with 10 woods each time, once produced 10 seedlings, another time 18.

My problem is with this assembling machine that does not produce constant number of seedlings and I can't set a stable production chain.

Thanks for the screenshots.
You are actually looking at the recipe for seedlings that Bobs greenhouse adds. Mine is on the same tab, look at the 1st one on the 3rd row. Thats the one B.I. adds. Gives you seedlings and pulp.
Bobs random output is intentional. Not all seedlings survive.

Hope that helps.

Oh, ok then. Would be nice to have such information straight on the screen about variable output then. Thanks for the clarification.