Continuing with my series on the twelve-step sensor-selection process, this month I'll look at the best practices for soliciting bids for the devices you've specified. Remember, your aim is to obtain price quotes from two to four qualified suppliers. The vendors should meet the requirements established by your purchasing department. At a minimum, they must be stable businesses, with reasonable expertise as attested to by several users. And they must have an established measurement quality assurance program, such as an ISO 9001 certification.
Working with Company Buyers
You've done the homework described in the first six steps of selecting a sensor. Now it's time to send your specification to the vendors you've chosen. You're probably working with your company's purchasing department, a process that has its pluses and minuses.
Your company's buyers look to you for guidance in evaluating your specification and will often test you by suggesting you relax some of your technical requirements to get the best deal. Their priority is to get the biggest bang for your company's buck; yours is to get the best measurement device for the application. You'll reach a happy medium, but not without give and take.
Don't hesitate to speak up and make the case for adhering to the letter of your specification. If you've got an item in the spec that cannot be relaxed, stand your ground. Often, you will have to provide the buyer with chapter and verse as to why it can't be changed.
If you've over-specified the requirements, the exercise will give you a chance to rethink some of the finer points. But if you're spot on, don't give in. Make your case and earn the buyer's respect with sound technical reasoning. He or she wants to be sure you are competent, but at the same time, will negotiate with you to save time and money. That's especially true if the purchasing department has already negotiated blanket prices for similar products or if one or more of the vendors you have selected are not on the company's preferred supplier list. These days, that means the vendors have passed quality-assurance screening and are suppliers of long standing.
One of the key items to check is that the vendors offer traceable calibrations for their devices. You've already verified that about the vendors you have selected, but do the vendors on the preferred supplier list meet these requirements? You may need to work with your company buyer to ensure that suppliers added to your list have those special qualifications. If unsure, you may have to add an item to the solicitation documents requiring a sample copy of calibration certificates and traceability statements. If any of the suppliers you've chosen are the key vendors for the type of sensor you are looking for, you should include supporting information in your specification to get the buyer to qualify them and request bids.
If your buyer tells you he or she can't or won't buy what you need, you have to put your foot down and insist. It can be done, even if the vendors aren't prequalified. You don't always win, but work to get what you need and cut corners only as a last resort.
You should track the bids throughout the solicitation process to ensure you hear from the people you have chosen. And don't forget to review all the exceptions to your specification proposed by bidders.
You can read more about techniques, tips, and rules for professional buyers at businessballs.com.
Doing It Yourself
If you work for a small company or are a one-man band, you may wear many hats and do the specifying and buying yourself. In that case, if you have been diligent and followed all the steps I have suggested earlier in the series, your path is set, and your due diligence done.
Contact the vendors you selected and send out solicitations. Give them a reasonable amount of time to respond. One month is usually adequate for a detailed specification. Require all vendors proposing exceptions to your specification to provide supporting arguments, and encourage them to offer bids on any reasonable alternatives, again with supporting documentation.
Some vendors are very clever and can provide you with remarkable insights, especially if you are approaching a new measurement. Learn from their expertise and experience.
Finally, ask all bidders to verify your early findings about their traceable calibration capabilities, and if you don't already have copies of their forms, request them. You can't repeat this step too often. Calibration and traceability are not something you sort out after the measurements are done. You begin with the specification and purchase of the equipment.