The Obama Administration has stated that 106,000 people have managed to sign up for health care on the Healthcare.gov site, a site 3-1/2 years in the making. Both HHS Director Kathleen Sebelius and Deputy Chief Information Officer for the Center for Medicare & Medicaid Services, Henry Cho, have been grilled by mittees as to the incredibly poor performance of the website. What exactly went wrong? NPR’s All Tech Considered breaks it down.

There are two popular methods of software development. The first is “waterfall:”

Lists huge requirements up frontAllows developers to leave project for lengthy periods of timeExpects a huge product

The “agile” system works in this manner:

Work is broken into phasesParts of the overall system are delivered on a regular schedule throughout the process“Glitches” are discovered – and fixed – along the way

Healthcare.gov was built using the “waterfall” method. The software and the system used to build it was reviewed by outside consultants McKinsey & Co. in March 2013.

Even though it was written in March, the slide sums up most of the key problems we eventually saw with the rollout of HealthCare.gov last month: limited testing time, evolving requirements, over-reliance on contractors and “stacking” of all the phases of development. The really damaging decision, according to the consultants: launching “at scale.” The exchanges for all 50 states opened on the same day, instead of a few states at a time, gradually opening the marketplaces in phases.

Consultants shared this presentation with many key people in the Obama administration, including Health and Human Services Secretary Kathleen Sebelius. The overall document warns of the waterfall approach’s many problems for this project, as well as those unrelated to the style of software development process government was using.

Consultants noted there was no clear leader in charge of this project, which we now know contributed to its disastrous release. And there was no “end-to-end testing” of its full implementation, something we now know never happened.

The full report can be read at “This Slide Shows Why Healthcare.gov Wouldn’t Work At Launch” at NPR.