The chief financial officer, chief technology officer and head of corporate and commercial are all leaving NBN Co, the company charged with rolling out the National Broadband Network.
CFO Robin Payne, CTO Gary McLaren, and Kevin Brown, who is responsible for the government-owned company's agreements with Telstra and Optus, are all departing.
The departures come in Bill Morrow's second week as NBN Co CEO.
In a memo announcing the changes to NBN Co staff, Morrow wrote that the five most common factors holding a company back were a lack of alignment or uncertainty on goals, "unclear or redundant accountability with a confusing organisation structure", "Inadequate decision making, performance tracking, and results orientated action/re-action", "Poor process management", and problems with culture.
"In my early reviews, many of you have suggested that we too need to address these five areas," Morrow wrote.
Starting from 1 May NBN Co will move to a new executive committee structure that is "process based and will emphasise an internal customer-supplier relationship model"
Reporting directly to Morrow will be chief strategy officer, JB Rousselot; COO Greg Adcock; chief customer officer, John Simon; head of legal Justin Forsell; the CFO; "chief culture and transformation officer" Bradley Whitcomb; the yet-to-be-appointed head of media relations; and head of regulatory affairs, Caroline Lovell.
Whitcomb, Vodafone's chief strategy and business transformation officer, will join NBN Co at the start of May.
The CTO function will now report to the COO, Morrow wrote.
"I would like you to join me in thanking Kevin, Robin and Gary. Appropriate farewells will be organised to celebrate their contributions," Morrow wrote in his memo.
"In an ideal world we would be able to announce all of the changes that flow on from the new structure, however as you can appreciate there is still more work to be done to get this right.
"You can expect to hear more from me and the Executive Committee on the changes as we progress, as well as answering your questions as part of roadshows I’ll be doing in May."
NBN Co has gone through significant leadership changes since the Coalition victory in September's election.
After last year's election, the new communications minister, Malcolm Turnbull, tapped former Telstra CEO Ziggy Switkowski for NBN Co chairman. Turnbull promised a " total change of management culture" at NBN Co.
One of Switkowski's first actions was to hire former Telstra exec JB Rousselot as head of strategy and transformation at NBN Co, leading the review into the organisation's operations and the rollout of the National Broadband Network.
Morrow was announced as CEO in December.