You may think that you are doing everything right. You've done your homework, worked up a relationship with the client, done your bid/no bid analysis and qualified the opportunity. Everything seems good...but sometimes we get caught up in things and forget the basics.
Basics such as answering the questions. Maybe this blog entry should be entitled what doesn't win work because this is about something that can sometimes get overlooked. There is more than one large organisation out there who spent a lot of time, effort and money preparing the groundwork for a large piece of work that they thought that they would have a good chance of winning, yet not only did they not get the work, they were dismissed by the commissioning organisation at the pre-qualification stage.
Why? That's easy - they didn't answer the questions properly. It's unusual to be writing a proposal an not refer to the RFP to make sure that the proposal is answering the questions - not so unusual that the questions aren't answered fully or in a persuasive manner - but a PQQ is often left to a junior member of the team who just cuts and pastes from other documents. It can be a costly error to not even get invited to tender for an opportunity that suits your business strategy.
The moral of this story. Take care and take time to check that what you are doing is in fact what you were supposed to be doing.