ERP Software Tier Definition
There are hundreds of ERP packages. Larger companies tend to require more complex financial structures, multi-currency and departmental organisation whilst smaller companies may be able to implement a package straight "out of the box". For this reason ERP software is often divided into tiers as a convenient starting point for software selection. If you use software designed for a different size of company from your own you could either be spending too much on "feature rich" (i.e. complicated) software or you could end up with software that does not have sufficient functionality or flexibility for your business. There is no absolute agreement on which software fits into which tier. Many software providers attempt to provide cut down or 'lite' versions to open up sales in lower tiers of the market.
There are no prizes for pioneering work in using software packages. Unless the package you choose is well supported locally, the chances of a successful implementation are seriously reduced. It is also worth saying that there is little correlation between the software and successful implementation. More important for a successful implementation than the choice of software is the method of implementation. You will find some sound practical implementation advice in the ERP Class "A" Implementation Toolkit.
You can see examples of packages in each tier, the current owner or "stable" and the number of times the products have changed hands at the ERP Graveyard Scorecard.