Writing PhD thesis as part of consortium project I am a PhD student currently writing up my thesis which was performing data analysis as part of a consortium project. 

For a number of reasons the project has stalled due to poor planning, lack of expertise, personality clashes etc. This means that the paper describing the dataset has not yet been published, and in it's current state I can't see how it ever will be.  My research is  based upon the analysis of this dataset. There were 4 people working on the analysis for the project, and whilst we were all involved in the design, people took ownership of particular parts, and the end product is a bit of a disjointed mess - a classic case of “too many cooks spoil the broth”. 

In my thesis, I have to include two pieces of analysis that were  “led” by some of the other consortium members as they lay the foundations, and it would not be a coherent story without these sections. In the preliminary unpublished paper, these two pieces constitute two figures and are brief, incomplete, and in my opinion not methodologically robust.  In my thesis, I have performed my own much more substantial versions of these analysis, and with what I consider a better approach which better fits my own work and story. 

My analysis represents my own view of the data which has been expanded greatly however, it still  addresses the same question and several of the same general conclusions are found. My questions regards how to properly navigate the authorship of these pieces and place the appropriate amount of credit with the people who did these preliminary analysis. I do not want to sign over credit for work where it is not due.  Does anyone have any experience with this type of issue regarding authorship of works on consortium projects, particularly within PhD projects, or any general advice?
A thesis is not an academic paper - you are supposed to be a little bit more self-centred than usual to show that you have applied the right kind of thinking to the problem, and the right methods.
Since you have re-done a lot of the analysis yourself because the collaborators did a poor/uninterested job, I would acknowledge the collaborators in the acknowledgements section at the beginning of the thesis, but then stick as much as you can to the work you did and the story that follows from there.

The alternative is that you don't talk about the work you did (bad idea), and might even give the reader the impression that you didn't know better having signed off on a sub-standard analysis (also bad idea).

Also, as someone in a similar situation, can you raise the issue with someone at the consortia? They need to know that PhDs are having a hard time forming a traditional "thesis" of work when they are being dropped into a service role rather than a traditional open-ended PhD, and that funding in the future must go to the labs that have thought about this problem in advance.