The death of any project is pretty straight forward, scope creep.
Hence, the perennial problems with Government implementations, whether CalPERs or LAUSD, you have a byzantine set of contractual obligations resulting in a myriad range of pay categories that simply, cannot be changed.
Any good private sector project when implementing an ERP solutions standardizes and aligns processes first, the Government can’t. Those esoteric pay rules in LAUSD codified via the contract. The pensions rules are to and hence, you have a bazillion rules because there is one set of rules for employees starting this year, different rule for the employees before last year but not yet retired, a different set of rules based on which role they’re in etc.
Any private entity dealing with the same sprawl of requirements and same restrictions on streamlining those requirements, really ends up with the same results, ERP projects running over budget, over time and racking up hundreds of millions in fees.