Some IT consultants drive profits via a storefront; others wouldn’t touch retail using their fiercest competitor’s budget. I don’t think IT consultants targeting commercial clients have much business managing a store. When’s the last time someone walked in off the street and asked to buy a dual-CPU 2U rack-mount server? It’s usually a residential user hoping to score a $399 cut-rate laptop capable of editing video while drafting three-dimensional CAD drawings.

I’m not suggesting that your consultancy keep a lot of inventory in stock, but there are five items I think your office should keep on hand at all times.

1: Basic desktop computers

Clients, especially business clients, often need desktops in a hurry, and many refuse to purchase spares or depot machines until it’s too late. We’ve seen it too many times in my office, so now we keep several desktop computers in inventory. We sell several each week simply because we have them on hand.

IT consultants often decide to try to repair a client’s failed four- or five-year old system because the client needs it back up and running fast. The computer in question is desperately needed to print checks, take orders, process lab results, check-out customers or patients, operate a machine, or process critical email, etc. (we see these scenarios each week). If you have a replacement system ready to go, it can significantly reduce client downtime.

The systems you stock don’t need to be fancy; in fact, a desktop chassis with an Intel Core 2 Duo, 2 GB RAM, Windows 7 Professional (32-bit), and a 250 GB hard drive meets a tremendous variety of client needs.

2: Basic laptops

Laptops fail more frequently than desktops due to the wear and tear mobility inflicts. Also, clients usually can’t seem to wait when they want a laptop; for instance, perhaps an executive drops a laptop and needs a replacement fast or an IT staff member is taking an unexpected trip.

Stocking a laptop that meets everyone’s needs is a tough task, though. Almost everyone wants a unit that is as light as a netbook, as stylish as Apple’s MacBook Air, and as fast and capable as an Alienware M17x. Yeah, that’s not gonna happen.

But here’s what you can do: You can keep a couple of Dell Latitude E5410s, HP ProBook 4520s, or Lenovo ThinkPad Edges on the shelf.

3: Hard disks

Hard disks are like oxygen in this business — you have to have them in all kinds, shapes, and sizes. IT consultancies should stock internal desktop and notebook drives, external disks up to 2 TB, and potentially even SCSI disks if your office supports a large number of servers with those drives. We often bill hard disk sales faster than we can reorder them, so stock up.

4: Routers

Networks and underlying routers provide the backbone infrastructure that power businesses. Thunderstorms, electrical surges, corruptible firmware, and other threats often prove fatal to critical network communications, including email, Internet, credit card authorization, cloud-based applications, remote sites, and other operations.

Your IT consultancy should not have to tell a client their business operations will be down 48 to 72 hours while you’re waiting for a replacement router. Keep replacements on hand.

You should stock SonicWALL TZ 100s and SonicWALL TZ 200s because they’re inexpensive, provide extensive QoS and VPN capabilities, and even offer optional gateway security subscription services. Plus, they’re worth their weight in gold by serving as a temporary unit until a larger, more powerful or specialized replacement can arrive.

5: Microsoft Office

How many times has a client asked you this question? “Microsoft Office isn’t included with a new computer?” Clients — regardless of their technical sophistication or intelligence — are often surprised that the popular office productivity suite doesn’t automatically ship with Windows. In our experience, what’s even worse is that most clients don’t understand they cannot transfer Office licenses purchased with an old PC to a new computer. New licenses are required.

Microsoft’s made suite selection easier with 2010. Microsoft Office Home and Business 2010 includes Word, Excel, Outlook, and PowerPoint, which meets most users’ needs.

What’s on your inventory list?

Symantec Endpoint Protection licenses, network adapters, wireless access points, battery backups, surge protectors, 14′ Ethernet patch cords, USB cables, and potentially even a laser jet printer are among other items my consultancy regularly stocks. What items do you stock? Join the discussion.