By Michelle Reichlin and Dr Lisa Lang

 All else being equal, the lowest price gets the job because quality and reliability are a given, right?

If you’re purchasing “off the shelf” parts that are generally considered to be the same, you can be relatively safe choosing a supplier based on price. If multiple customers are buying the same “off the shelf” parts, then mostly likely multiple suppliers have these parts on the shelf. When this is the case, the risk of purchasing the lowest price part is minimized. If you do run into a quality issue 1) the part is in stock, so your current supplier can quickly replace it with another part, or if it’s a supplier issue you can purchase from an alternative supplier; and 2) since the part is in stock, the lead-time is small (shipping time) reducing the likelihood of missing your due dates and jeopardizing your customers.

The challenge, of course, is how to choose a supplier when the job is — custom, hard to hold, precision machined castings — and most likely, not everything else is equal.

When you’re purchasing a highly custom part that is unique to you and falls into the category of a precision machined casting, AND it’s difficult to hold for the machining process – then – it’s not just about price.

If the supplier of this highly custom part falls short on quality …

  • there are no parts on the shelf at your current supplier or with any alternative suppliers to allow quick replacement.
  • replenishment time is long. Replenishment time includes raw material lead-time (castings can take weeks or even months), manufacturing lead-time, and shipping lead-time.
  • hard to hold castings typically require custom fixtures to allow the unique shape to be machined. This means that the custom fixture also needs to be engineered and manufactured.
  • Then, you are very likely to miss due dates, increase your time to market, reduce cash flow and endanger your customers. You have to consider the cost of not having the part when you need it.

So, the risk of bad quality in the case of highly custom parts is much greater for you and your customers. But, how do you ensure you’re choosing the supplier with the quality you MUST have but at a competitive price?

You typically don’t know the quality is bad until it’s too late. And EVERY supplier says that they can do the work and that they have great quality. But, how can you be sure?

You can’t, but here’s what you can do to minimize risk:

Choose a supplier that specializes in the area of your unique demands.

How does this help?

price-vs-quality-precision-machined-castingsIf you needed a tumor removed from your brain, you wouldn’t go to the lowest cost provider or to a general practitioner. You would look for the best brain surgeon in your area and if it were a really delicate situation you might look for the best in the country or world. Then amongst the best, you might consider price and lead-time, depending on how dire the situation. Lead-time, in many cases is no less important than quality or price.

In the case of hard to hold precision machined castings, here are 3 strategies to consider when looking for a supplier.

  1. Look for a supplier who is communicating across all their collateral that what you need (precision machining of hard to hold castings) IS there area of ANNOUNCING-speciality-hard-to-hold-precision-machined-castingsspecialty. If they are just claiming to be a precision machine shop with tight tolerances, they may not have enough experience with hard to hold castings that will reduce your risk. If they’re not proudly announcing it, maybe they CAN do it, but you don’t want to be their practice.
  2. Look for a supplier that engineers and machines the custom fixtures needed to hold the unique shape of your casting IN HOUSE. If they truly specialize in this, they’ll be doing this in house to 1) to control the quality of the fixture. Because a bad fixture will cause a lot of headaches and rework; and 2) reduce their lead-times for acquiring the fixture.
  3. And, look for a supplier that has due date performance over 95%. A great shop can provide a due date that they’ll hit 95% of the time and when they do miss, it’s by days, not weeks. Many suppliers of custom machined parts have very poor due date performance despite their promises. A good supplier may not always be able to give you the promise date you want, but they should be able to tell you what they can do and then do it 95% or more of the time.

A good potential partner for your custom parts will have likely come to the rescue more than once. Ask questions to find out.

Case in point: Contour Precision Milling had a prospect (let’s call them ACME to protect the guilty) for whom they quoted several parts several times, but never got the business because their price was a little higher than another supplier’s. A few years later ACME ran into a problem with one of their suppliers. The supplier was faltering on quality and ACME was in a bind despite pleas to the supplier.

Contour’s engineers met with the design engineer at ACME to learn what was important and where the problem areas were. Together the GD&T was revised to insure that the parts were both functional and “manufacturable”.

To get ACME out of the bind, Contour reworked the parts from the previous supplier back to specification. To do this Contour engineered and manufactured the right custom fixtures in house, allowing ACME to ship the parts in record time and resume generating cash flow.

Contour’s engineering ability and willingness to rework another supplier’s part saved a lot of time and money. In addition, because Contour could engineer and build the custom fixture in house, this shortened the lead-time even further. Without that, ACME would have had to order (2 months lead-time) and pay for new castings and then wait and pay for another manufacturing cycle.

Many precision machine shops have stories of gallantly coming to the rescue of a customer. But make sure you check out, as Paul Harvey used to say “the rest of the story”.

Do they continue to be on-time at least 95% of the time on first date given? When they do miss, are they missing by days or weeks or worse? Are they delivering in competitive lead-times?

And most importantly – do they specialize in YOUR needs or are you practice?

Today, Contour makes all of ACME’s parts when and as promised. This dependability allows ACME to focus on other things. Isn’t that the way it’s supposed to be?

Precision-Machined-Castings2014 Copyright Michelle Reichlin and Dr Lisa Lang, all right reserved.

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