There are many reasons why projects (both simple and complex) fail; the number of reasons can be infinite. However, if we apply the 80/20 rule the most common reasons for failure can be found in the following list:
Poorly managed Undefined objectives and goals Lack of management commitment
Lack of a solid project plan Lack of user input Lack of organisational support
Centralised proactive management initiatives to combat project risk Enterprise management of budget resources Provides universal templates and documentation
Poorly defined roles and responsibilities Inadequate or vague requirements Stakeholder conflict
Team weaknesses Unrealistic timeframes and tasks Competing priorities
Poor communication Insufficient resources (funding and personnel) Business politics
Overruns of schedule and cost Estimates for cost and schedule are erroneous Lack of prioritisation and project portfolio management
Scope creep No change control process Meeting end user expectations
Ignoring project warning signs Inadequate testing processes Bad decisions