PwC to investigate ATO's system collapse

The Australian Taxation Office has followed through on its promise to commission an independent review into the "worst unplanned outage" in its history, appointing PwC as its lead investigator.

The tax agency today said it had chosen PwC because of its experience working with the HPE SAN network at the centre of the bungle.

The collapse of the storage network on December 12 caused huge problems for the ATO, downing its entire online presence and several internal systems for two days.

A second outage in the week following the December 12 collapse caused more problems for the agency, which was also forced to conduct critical maintenance work for four weekends in a row over the Christmas period to stabilise its systems.

It took the ATO until the second week of January to fully restore all affected services.

In the days following the initial hardware failure, the agency promised to conduct an independent review to find out what went wrong.

The review will cover the nature of the failure, the root cause, the adequacy of back-up and contingency plans, the likelihood of recurrence, as well as the response by the ATO's vendor partners, including HPE.

"The review will help us to fully understand what happened and why, and what needs to be done to ensure we are not exposed to this type of incident in future," the ATO said today.

The PwC report will be finalised in March.

The ATO is also undertaking its own internal review, focusing on "key stakeholders" like its software developers and tax professionals.