Minimum order quantity vs package size not clear

[christianlupus]

Bug description

The user can add multiple distributors to a part each associated with a price and an "order volume amount". This amount is not handled consistently throughout PartKeepr:

• On the distributor's configuration page, it is called a packaging size
• During project price calculation it is considered the minimal number of parts ordered.

To make the difference clear: The packaging size is fixed and you can only order in chunks of this amount. Like you can either by a whole reel of 5000 SMD resistors for the small price or not. You cannot buy half a reel.
The minimal number on the other hand is not fixed. If you get a discount starting at 100 pcs and you 105, you will still get the discount.

There might be other side effects I do not see at the moment.

We need to decide what behavior we want now and adapt to this decision. So this issue is less code related but more of a design decision.

System Information

• PartKeepr Version: 1.4.0
• Reproducible on the demo system: Yes

[berndoJ]

In my opinion if one of these two options has to be chosen, I would suggest the "minimal number of parts ordered" option. I think that it would be a lot more useful than the other option, as it is more common. Additionally, interpreting the package size as like a package, like a reel, additional code has to implement the cases where the needed number of parts is not a multiple of a package size. Let me expemplify this:

Imagine you need 5203 resistors for your project and you can order a reel of 5000. Then you would need to order a reel @ the reel cost and 203 extra resistors @ 1 resistor cost. Then Partkeepr would have to calculate a compound price. Thus a way of dealing with compound prices has to be implemented (either create two separate ordering lines or just add the prices together?) What if the ordering number of the reel is not the same as the singles? Then this would lead to a problem.

I think that implementing package sizes such that you can only order a multiple of them would need a lot of redesign and implementation for the usefulness it would have. I doubt that most Partkeepr users order components in the tenthousands and that interpreting the package size as a price step would be much more useful, logical and easy.

[christianlupus]

I think the minimum number of parts option is the better interpreation for the common sense. Then, some texts need to be replaced on the GUI, merely. Also, this makes your PR more sprecific to test.

The other alternative is in #1134. I assume the lot-based approach will not bringm uch benefit for the average user but I put it here for reference.