I was recently part of a project to implement PeopleSoft modules for payroll and human resources.

I think ERP systems are held in high esteem because they have a reputation for providing mature data models with mature front ends that can be used to integrate many of a business's data systems on a large scale. For the most part, I think that SAP and PeopleSoft and the others accomplish this.

From what I've seen, the data models are very mature. The fields that are needed are there or can be put their by configuring rather than customizing the system. There are many tables that are highly normalized. These systems are often robust enough that implementation will include some configuration but no customization of data structures or code. The only customization is usually for interface files to pass data between the ERP system and any outside systems that remain.

For reporting, PeopleSoft uses PeopleSoft Query, SQR and Crystal Reports which are all embedded into the PeopleSoft product. Note: SQR is now sold as Brio.Report by Brio (www.brio.com).

ERP can be overkill for smaller businesses. For larger ones, the robustness and integration can be wonderful. It is very attractive to implement a system that is already known to work well rather than to try to write something that is custom. Many business processes are standard and their is no need to operate them on a proprietary system.

In the future, initiatives such as Microsoft's Biztalk framework for XML are likely to standardize data formats for standard "documents" such as purchase orders, invoices, etc. even more. More and more of these documents will pass electronically.