WHEN e-business was new, some debunked enterprise resource planning as outmoded and irrelevant. Then ERP vendors like SAP, PeopleSoft and J.D. Edwards became Web-enabled and began to introduce bolt-on business-to-business and front-end modules for supply-chain management, CRM and other functions. ERP -- traditionally thought of as managing back-office processes like finance and human resources -- seemed to have gotten lost in the shuffle.

But ERP has experienced more than one demise and resurrection. To judge from a recent Accenture survey of executives in mid-sized and large companies, ERP still looms large on the radar screens of business decision makers. For example, the Accenture study shows that 22% of the executives surveyed believe that an ERP implementation was their company's most beneficial technology investment over the last two years. Asked to identify the next big wave or killer app in the business world, 11% percent of the execs said ERP. Not a huge number, but only four percentage points behind the more en vogue SCM. And, don't forget, we're talking killer apps here.

Ten years ago, ERP was all the rage. Its value proposition was to provide connectivity among independent business functions, to cut inefficiencies and to streamline business processes. Traditional business functions existed like isolated stovepipes, with one function dumping into the other and into the next. ERP enabled a process-oriented view of business by allowing for planning and execution across those functional stovepipes. The press reported stories of ERP implementation disasters, but these totaled only a few dozen out of tens of thousands of implementations.

When e-business came along, some sought to promote its extended enterprise orientation at the expensive of ERP's focus on the internal enterprise. ERP's heyday, said its detractors, came right before the Internet emerged as a viable electronic business platform. At one point, ERP implementations plummeted in the face of the rising e-commerce tide.

That trend, evidently, has not lasted. Increasingly, ERP came to be viewed as an enterprise information backbone over which other enterprise applications were overlaid. ERP sets up standard processes by which companies handle transactions and has proven itself particularly adept at consolidating the purchasing functions and in tracking the total costs of transactions. ERP can feed this transactional data into other applications, such as logistics, supply chain or product data management solutions -- there to be organized and optimized for the purposes of those processes and functions. No other basic technology platform has yet emerged to rival ERP as an enterprise systems architecture and business process controller.

As ERP vendors developed additional modules that were easily integrated with existing systems, the prospect of expanding the enterprise technology base with those modules proved an attractive proposition for some of the vendors' existing customers. An alternative is to employ application integration technology to stitch together best-of-breed solutions, a more expensive and laborious undertaking.

Another reason for the ERP renaissance is that vendors Web-enabled their technologies and began to use the Internet as a delivery pipeline. The combination of establishing ERP as an information technology platform and using the Internet to gain access to it adds up to quite an attractive solution.

Perhaps the most important reason for ERP's overcoming the e-business challenge is the failure of the original many-to-many B2B model. Now that e-business is increasingly focused on collaboration and negotiation -- activities that require one-to-one or one-to-a few connections -- the importance of robust and reliable enterprise systems has become re-emphasized. And, by becoming Web-enabled, ERP has vindicated itself as a key component of today's e-business architecture.

Implicit in the resurgence of ERP is a more profound discovery, especially for these uncertain times: that the enterprise still counts, that internal processes are still important to customer service and profitability and that a company cannot afford to be focused outwardly at the expense of internal systems, processes and efficiencies.