Let's say that my company was to develop a replica of MS Word (just as an example). What would be the bottleneck to the development process, assuming that one has infinite cash available and an organization like Microsoft? In other words, what are the most usual hindrances from developing such software fast? Let's assume that all specifications are in place and the organization is working perfectly, so we just focus on the software development until the product is ready to be shipped. Some alternatives might be:- Writing the code- Writing tests- Manually testing the end product- Rewriting the code due to poor design in the first place- Designing the code- Code review done by experienced developers- Designing GUI- Redesigning GUI based on alpha/beta-user feedback- Processing feedback from users- Waiting for alpha/beta-user feedbackPlease use references in your answer or state your experience on the subject. 
What are the biggest bottlenecks when developing large projects?
development process;large scale project
In my experience the major bottleneck is the learning process.  When your hypothetical company sets out to develop the next Microsoft Word there is a huge gap between what you need to know and what you actually know.  The size of the gap depends on many factors, it may be in technology or the domain.  You've touched on some of these issues in your question, e.g. design, user feedback etc.  Microsoft Word has been in development for over 30 years now so between the history, code, tools and people there is a lot of knowledge behind it.So if I were to try and do this I'd try and hire the best people with experience in the domain, both technical and management.  Try and read any available literature in the field.  I'd also try and get customer feedback as soon as possible.  The biggest problem is the critical things you don't know and may find out about very late in your process.This, by the way, is not unique to software projects.  It's true for every large scale project where you're trying to do something new.  E.g. look at the Boeing Dreamliner.  There are many books written about this.  The Mythical Man Month is one.