When purchasing software for your business function, one must consider the following:
The software vendor has two value propositions: 1) The capabilities already built in the software product.2) The vendor's capacity to add more capabilities over time. These values must be compared to: 1) the prioritized requirements of your business function.
2a) your assessment of the vendor's capacity to add capabilities to their software product.
2b) the alignment of your business function with the vendor's target market. These correlate to: 1) how little benefit you will likely realize during initial implementation.
2) how little benefit you will likely get from future releases of software product. These are compared to: 1) how much it will cost you to purchase and implement the software.
2) how much it will cost you to maintain and upgrade the software over the lifetime of the application. If you need to customize the product, or you need to pay the vendor extra to customize or develop capabilities so that you can accept the product, these change the cost/benefit ratio as well. A bird in the hand is worth 2 years worth of customization – by either you or the vendor. If the product must be integrated with other systems in use at your company, those costs must be considered, as well as integration testing whenever either end of the integration changes. In either case, whether you realize it or not, you are entering a partnership with the vendor, if the vendor doesn't act like a good partner, they probably won't be. Their corporate issues can become detrimental to your product implementation. Their staff choices can have tremendous impact on your ability to get your project done. Their vision for their product can easily move away from your companies goals. The cost of replacing the customized or integrated software will be higher than otherwise, and in all likelihood, the value delivery will be lower than expected. Choose wisely, it pays to be careful, when making such decisions.