The absolute hardest part of managing a company, is balancing cash flow. That is why you should always buy the pieces of equipment that your IT team asks for.
The reason is simple: qualified engineer are expensive while hardware is cheap. When buying new hardware, it is always a good thing to compare the price of said hardware with the value of qualified labor.
As a gross approximation, I tend to consider that in IT, a junior should generate over 250€ of value per day for the company, an experienced employee over 350€ and a senior over 500€. That means that a small team of two junior, one experienced employee and a part time senior is valued at 1100€/day.
So this big 9 000€ server that they are requesting, is worth about 8 days of work. If they cannot buy the server, what is the probability that they will find a workaround, test it and bring the project on track in a week and a half ? Not much. And what is the probability that they will have to find convoluted solutions to make for the lack of this server ? Quite high. Also not buying will build up frustration in the team.
It is as simple as that. If you trust your team - that is you believe that if they ask for something it is because they need it - you should buy them what they ask for.
This said, there are a few pitfalls here and there. The first one is that the IT team is not immune to what is called hype. Hype is a shortcut for hyperbolic advertisement, the kind you would have at a circus entrance or at a mall product showcase. Marketing is very good at turning something you never heard about, into something you absolutely need. So if a product is new on the market, and your team never reported on the problem it is supposed to solve... You definitely can say no. But be ready to reconsider.
Another problem that may arise, even in the best teams, is cargo cult. Cargo cult is when people expect that a new version of a product will solve all their problems, and bring fantastic new functionalities. So if you are currently using version N-1 or N-2 of a specific hardware, and your team absolutely wants to switch to version N, be wary. Ask questions and make sure your team can defend the new product with solid arguments. No product solves problems "automagically".
This is well - but what about the real world?
I know that most company do not have the cash flow to buy everything their team ask for. Acquiring equipment that will ensure a faster delivery is good, paying bills and salaries is better. If there is no way to afford the new hardware, you must refuse the purchase quickly.
One of the worst answers is "We will see about this next month/next quarter." How is a team supposed to handle this answer ?
Should they switch to another part of the project? That will result in planning changes, and loss of focus.
Should they continue assuming they won't get the equipment? Meaning they may have to scrap part of they work if they do.
Should they do a double development? One development for the case where they get the hardware and one for the case where they don't?
Saying no quickly makes the project easier to manage. It may not be the best option, but at least it keeps the team on track.
Worst case scenario
Making your team wait is only the second worst situation. Control management to the extreme is what you should try to avoid at all cost. In some companies buying anything more expensive than a pencil is a lengthy and tedious process. There is need for control in procurement, but this control must be reasonable. IT teams have a cost/value per day, but so does everyone else.
Having to go through numerous meetings and processes to get a purchase approval can turn into a total waste of money. Directors, control managers, service managers etc. have a value of at least 50€/hour. Sometimes much more. If a buying process will cost more money to the company than what you are trying to buy (and it happens a lot), bypass the process. Ignore hierarchy, go see the person that has the power to approve a budget raise on his own and plead your case.
No matter how strict and corporate the place you work for is, making a company loose 10 000€ worth of employee value to buy a 9 000€ equipment is stupid.
This is the true sense of what I mean when I say that in IT hardware is free. Doing a proper audit, writing a report, pleading your case to various directors and project managers must not end up costing as much, or more, than the equipment itself.
illustration by user BlickPixel on Pixabay : here