Wow this topic is surely hard to find in the internet. Good thing that the reference i had on our previous assignment has infos about the barriers of IS. Altough http://www.ctg.albany.edu/publications/guides/tying?chapter=3&section=4 is about state-local IS, it has insights of what hinders an IS project. And heres some of it:

Lack of a shared, reliable computing and network infrastructure.
- When an institution lacks an IT infrastructure there will be a dificulty in operating technology supported programs with consistency from one office to the other or building to building. It also slows and complicates communication among the organization or other institutions

Unrealistic time frames.
- Some information systems take considerably longer than originally planned. Time delays lead to serious difficulties in planning for and adjusting to changes in operations. Since they consume more time than they expected, the deadline will become a pressure.

Goals that are too ambitious for the resources available to achieve them.
- When planning a system there is a certain goal that comes with it. It inspires the staff in making the project. But when the goal is a bit afar considering the staff, equipment and funds alloted, the said goal will be hard to reach. Even well planned projects tend to fail when their goals and resources are on different scales.