How do you decide when to introduce a variant?

[garyfeesher]

Hi forum,

I am working in the electronics industry, and my company constantly faces the problem of not knowing when (or whether) to introduce a variant to a circuit board. It is very difficult for us to calculate the cost of having a variant. We particularly struggle with understanding whether it makes sense to add a variant for smaller volume circuits.

In short, I am trying to develop a way to take in data about a certain circuit (probably the Part prices from the BOM), and then develop a trade-off curve to help make the decision. The problem is, I am having trouble identifying which variables to bring him, how to go about creating this curve, and what tools are best to use. I am thinking of using a similar approach to a "break-even chart", where the total variable and fixed costs are compared with the volume and cost to identify a break-even point. But even with this method, there are differences between what I want to implement and what these charts are typically used for.

An example may be the development of a circuit that needs to be used in both the United States and in Europe. The common question would be, do we make one circuit that works at the two different voltage levels, or do we create two circuits, each tailored to their respective regions?

ANY insight into this type of analysis would b greatly appreciated! Whether it's a method you've used, your company has used, etc...

Thanks!

Gary

 

[VEBill]

Random points:

PCBs can often be designed to be stuffed in several ways. So many CCA variants, but all using one PCB.

Successful companies would want to drive down their NRE, lead time, and minimum (cost-effective) build Qty. If these are driven low enough, then the whole question is turned on its head. Semi-custom build to order.

 

[itsmoked]

I agree with VE1BLL's angle of trying to keep the board the same for all the variants. These days boards are pretty cheap so it isn't necessarily for the sake of the PCB but more because everything else that goes into the number gets to be the same. The same connectors, test jigs, mounting holes, etc., etc..

The only tools I know of are the trusty ol'spreadsheet with costing for every single scenario. The hard part is quantifying things like the cost of different test jigs and the more if-than issues tech-support needs to understand and support.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[garyfeesher]

Thanks for the responses, guys.

More specifically, I wonder if there is any way to automate the cost-per feature process so that the engineers don't need to recreate the template every single time they want to do an analysis?

 

[itsmoked]

Not a chance. Sorry, it takes some work to get something you can actually put some trust in. There are no shortcuts or canned products that you can trust to do even a marginal job of this.

One of the most time consuming aspects is getting the price break quantity numbers to do these studies with. Digikey and Mouser are getting much better at sucking in your BOM in a couple of formats and generating an order which of course has all the extended totals and grand totals.

I'd use that to live-populate your spreadsheet with component costs.

Keith Cress
kcress -

http://www.flaminsystems.com