A number of reasons can be proffered:
Firstly, procurement and financial departments are often unfairly tasked with procuring new ICT tools whilst being ill-equipped to do so. In addition, the selection of an appropriate technology tool is by no means a trivial exercise and without the correct mix of expertise in the selection team key issues are easily overlooked.
Secondly, in reality, the influencing skills of a specific technology vendor account for a far greater percentage of the weighting of the decision made than does the intrinsic capability of the actual system itself. Organisations that make decisions primarily using a Type 2 decision-making style (Political) are most at risk as the influencing often leads to "corner cutting "during the decision making process. This increases the risk of failed expectations as the system fails to deliver due to a flawed purchasing decision.
Finally, the evaluation process is not inclusive of all the key elements needed to make a correct decision, ranging from an understanding of strategy to business process and operational requirements.