Why do many software projects fail today?
As long as there are software projects, the world is wondering why they fail so often.
I would like to know if there is a list or something equivalent which shows how many software projects fail today. Would be nice if there would be a comparison over the last 20 - 30 years.
You can also add your top reason why a software project fails. Mine is "Requirements are poor or not even existing." which includes also "No (real) customer / user involved".
EDIT: It is nearly impossible to clearly define the term "fail". Let's say that fail means: The project was more than 10% over budget and time. In my opinion the 10% + / - is a good range for an offer / tender.
EDIT: Until now (Feb 11) it seems that most posters agree that a fail of the project is basically a failure of the project management (whatever fail means). But IMHO it comes out, that most developers are not happy with this situation. Perhaps because not the manager get penalized when a project was not successful, but the lazy, incompetent developer teams?
When I read the posts I can also hear-out that there is a big "gap" between the developer side and the managment side. The expectations (perhaps also the requirements) seem to be so different, that a project cannot be successful in the end (over time / budget; users are not happy; not all first-prio features implemented; too many bugs because developers were forced to implement in too short timeframes ...)
I',m asking myself: How can we improve it? Or do we have the possibility to improve it? Everybody seems to be unsatisfied with the way it goes now. Can we close the gap between these two worlds? Should we (the developers) go on strike and fight for "high quality reqiurements" and "realistic / iteration based time shedules"?
EDIT: Ralph Westphal and Stefan Lieser have founded a new "community" called: Clean-Code-Developer. The aim of the group is to bring more professionalism into software engineering. Independently if a developer has a degree or tons of years of experience you can be part of this movement.
Clean Code Developers live principles like SOLID every day. A professional developer is the biggest reviewer of his own work. And he has an internal value system which helps him to improve and become better.
Check it out on: Clean Code Developer
EDIT: Our company is doing at the moment a thing called "Application Development and Maintenance Benchmarking". This is a service offered by IBM to get a feedback from someone external on your software engineering process quality etc. When we get the results, I will tell you more about it.
Answer
Bad management.
Projects are not successes or failures based on some underlying feature of the project, but on whether they fulfill the needs of the users. (They can fail altogether, in which case there was a gross misstatement of what was possible.) It is mostly in the process of evaluating the feasibility and cost-benefit ratio of the project, and establishing goals, that software projects tend to fail or succeed.
There's a disconnect between people who deal with facts and things (like programmers) and people who deal with other people (like sales types and managers). To a programmer, the facts are the facts, and have to be dealt with. To a sales person, the facts are what other people think, and are changeable.
There's also differences between tangible and intangible facts. Nobody thinks that workers could build a large bridge in a month if they were really motivated; they can see all the steel and concrete and other stuff that has to be moved and fixed into position. Software is much less tangible, and lacks the physical restrictions: while it is not even theoretically possible to build the bridge within a month, it is conceivable that a team could create a large project within a month, as "all" they have to do is get everything right the first time. It is physically possible to type thousands of lines of code a day; it's just that the chance that they're usable as is is so close to zero it doesn't matter. The actual productivity of a top developer is actually pretty unimpressive in word count, compared to (say) the productivity of a journalist.
Therefore, those who are used to flexible facts don't have the imposing physical limits to remind them that things can be pushed only so far, no appreciation for what programming actually requires, and no good feel for how much productivity is realistically possible. Moreover, they know how to get their way in negotiations, much more than the average developer, so in negotiations about what's possible they tend to assume more than they can, in the real world, get.
In the meantime, software development is inherently fuzzy, because producing the physical product is trivial. I can produce a copy of software quickly and cheaply, once it's been developed. Software development is design work, pure and simple. Anything corresponding to manufacturing is ruthlessly eliminated with such things as compilers and wizards and code generation. The developer, faced with the manager who wants the impossible, finds it hard to say the impossible is actually impossible, because there's no way to say it's actually impossible. Given facts that are unknown enough to feel flexible, the person with strong negotiating skills and determination will typically get the answer he or she wants.
Given this disconnect, one might ask whose responsibility it is to bridge it. The answer is, in my opinion, clear. The responsibility for understanding how different people think belongs to the people who specialize in dealing with other people. The responsibility for coordinating different types of people belongs to the people whose job it is to coordinate these things. Therefore, managers.
Managers who do understand software development and developers, and can deal well with other managers, will do well, and their projects will generally succeed. There are still far too many of the other type in the world.