How much time does your service team spend on parts? For many rental centers, the answer is "too much." Finding the right part can turn into an all-day affair, from identification to ordering and arranging delivery. Most rental companies have dozens of suppliers and hundreds of models, which translate into thousands of parts that are needed to keep the inventory running and rented.

Parts is one area in which e-commerce, for all its unfulfilled promise, can actually deliver a solution. Instead of leafing through massive parts catalogs and waiting on hold with ordering agents who may not be helpful, try the Internet, which offers the potential to seamlessly integrate millions of parts, according to PartsRiver.com, whose Web site was founded last year to target the industrial parts e-market.

But simply putting parts online for ordering isn't enough, of course - industrial and construction equipment is too complex. PartsRiver claims to have incorporated "parts expertise" into its software, so customers can find out which parts work together, which substitute parts will work and which aren't suitable.

For its commercial and business-to-business customers, Sears Roebuck has launched www.spdcommercial.com, which will offer access to more than 4.2 million parts, including Briggs & Stratton, GE, Kohler and Craftsman brands, among others. The site will feature searches by model number, frequently ordered items and previous orders.

PartsRiver allows buyers to search for parts with limited information even if it is only the make and year of a machine needing repair, a generic application, a part description or a single part number. Its database contains a half-million items from 800 manufacturers and includes 7.5 million cross-references. Categories include power transmission, electrical, engines, air compressors, lighting, gauges, hydraulics and shop supplies.