Project specifications
Too little / too much?
In this post we talk about balancing the length and especially the content of project specifications. What is too little and what is too much? How to specify your requirements? Let us spend some thoughts on this subject.
Balancing the project specifications
Specifications are necessary – there is no question about it. However, there is a principal question how deep the specification shall go. By specifying too little you might get an equipment or system not fitting for purpose. By specifying too much you might eliminate too many vendors and eventually you don’t find any solution. How to keep it in balance? In this post I would like to share some experience and give few hints that might help you to get the best product or system without costing you a fortune.
No. 1: Specify what you need. Specify the performance you expect.
- As simple as it sounds people often don’t follow this principle.
- If you need high availability, specify this availability. Do not specify what components shall be redundant, what internal material shall be used etc. Leave it up to the manufacturer to offer you a design that fulfills the requirements.
No. 2: Provide clear definition. Do not leave room for misinterpretation.
- Do you ask for high efficiency? You shall then provide a definition how the efficiency is obtained. Typical value, value with tolerance or a guarantee value without tolerance? With or without auxiliary consumption? Considering extra losses from harmonics or just sine wave value? If you don’t specify this clearly, you might get very different figures from the vendors. And the one with best efficiency on paper might not be the one with best efficiency in real operation!
No. 3: Know the background of your requirement.
- In case of extensive specifications there will always be (more or less) deviations from the potential vendors. Someone needs to decide if these deviations can be accepted or if they exclude the manufacturer from the tender. This becomes mission impossible if you don’t understand the background why this or that thing was specified. I have experienced such customer meetings where we got stuck because no one knew the reason of the particular requirement.
No. 4: Be open for alternative solutions if they are plausible.
- Variable speed drive systems are continuously developed. Therefore, it might be worth to listen to the manufacturers. Maybe they have an alternative solution for your requirement. Maybe that solution is even better than the one you have specified. Of course, these alternatives shall have a solid base as you don’t want to be the laboratory mouse. The alternative shall sound plausible and ideally had been tested or even commercially used before. Technologies and designs well proven in the field shall be a valid alternative to think about.
No. 5: Things that matter to you shall be contractually binding incl. defined penalties or compensations.
- If something really matters to you regarding variable speed drive system you should make this requirement part of the contract.
- Honest manufacturer shall not have any issue to stand behind promised performance.
- If there are no consequences the manufacturers can promise you many things depending on their level of moral and business ethics.
- Penalties/liquidated damages will discourage dishonest manufacturer.
Why do I give you above recommendations?
First because I believe that the competition shall be fair. Different manufacturers might have different solutions that provide equal performance. That is the beauty of diversity!
Second because it get be very costly for you. If you buy something cheap that cannot provide the requested performance then it was an expensive purchase for you anyway. If you specify certain topology or very specific features of one vendor in great detail, you likely discriminate other manufacturers.It will damage the competitive environment and you will end up with higher price and being dependent on just one supplier. Not even mentioning that it might be illegal, especially in public tenders!
Third because open dialog with the manufacturer allows you to be informed about latest development and interesting new solutions. If you strictly stick to your specification, you unnecessary close the door. I don’t ask you to accept any crazy idea sketched on a paper, but to be open for alternative solid solutions. You cannot lose, only gain!
References
[1] How to choose a medium voltage VFD – entire series, https://mb-drive-services.com/category/choose-mv-vfd/
[2] Selection of a variable frequency drive, https://mb-drive-services.com/selection-of-a-variable-frequency-drive/
[3] Medium Voltage AC Drives, https://new.abb.com/drives/medium-voltage-ac-drives
