A decade ago, the U.S. Army realized that the easiest way to get the many rarely requested, but vital, replacement parts to the troops, was to manufacture the parts in the combat zone. In short order, this led to the construction of a portable parts fabrication system, called Mobile Parts Hospital (MPH), that fit into a standard 8x8x20 foot shipping container. The key to making this work was the availability of computer controlled machine tools, which can take a block of the proper metal, and machine the desired part. The computer controlled machine tools have been around for decades, but the big breakthrough was the development of CAD (Computer Assisted Design) software for PCs in the 1980s, which made the process of designing, and fabricating, a part much faster. The MPH has a high speed satellite data link, which enables it to obtain the CAD file for a part. Many CAD files are already stored in the MPH. Often, the MPH staff figure out a way to improve a part, based on the broken parts they see, and what the troops tell them.
There are three MPH systems in service, one of them in Afghanistan. A fourth is being built, at a cost of $1.5 million. In the last six years, MPHs have manufactured over 100,000 parts, on the spot. This saves days, or weeks, that it would take to order the part from the manufacturer, and the MPH part is usually a lot cheaper (because the air freight and manufacturer mark ups to pay for maintaining the part in inventory). The next version of the MPH will have also have a 3-D part builder, which uses metal dust and a laser to build a part.
Not having sufficient spare parts to support wartime operations is nothing new. It happens again and again. The source of the problem is the ease with which one can cut spare parts stockpiles in peacetime. No one will notice it, and you will save millions of dollars. Better yet, you avoid some bad publicity when you have to dump millions of dollars worth of obsolete spare parts years later. This always happens when the equipment the spares are used for is replaced by new gear. You have a pile of spares you no longer need, and they are often sold off for pennies on the dollar. On a slow news day, the media will pick up on this as another government waste story. Unfortunately, if a war comes along, you need all the spares you can get. But wars occur infrequently, so there is always the temptation to hold back on building up an adequate war reserve of spare parts.
While everyone has religion about large reserve stocks of spares right now, the old timers in the logistics business know that once the fighting is over, some cost cutter will come along and shrink the war reserve. To try and mitigate that, the military is adopting more modern inventory tracking systems that reduce the time it takes to find the spares, and get them to where they are needed. This is particularly a problem when the spare parts are shipped to units in a combat zone. It's easy to track spares in a warehouse back in the states, but much more difficult once they are in a shipping container somewhere out there. Another solution is contracting with firms that can quickly gear up and manufacture spares in a wartime rush, as well as using the MPH.
But the one thing you can be sure of, no budget conscious peacetime military administrator will be able to resist cutting wartime spare parts stocks. You can bet on that.