"The changes are designed to drive an improvement in financial performance and generate greater customer relevance as customer needs change and competition increases."
Warehouse didn't say whether the new finance division will be affected.
The finance unit, which was launched in 2015 offering credit cards, insurance products and a pre-paid mobile brand, is expected to face a writedown in goodwill in the first-half accounts, and chair Joan Withers told shareholders last year the board was reviewing the outlook for it to break even in 2018.
Auckland-based Warehouse spent hundreds of millions of dollars overhauling its outlets and buying new businesses to drive future growth under the leadership of former CEO Mark Powell who Grayston replaced in late 2015. That had followed a period of underinvestment and sales decline in the late 2000s.
Last year the retailer embarked on a three-year plan to introduce new technology and use the company's scale to mine customer data for personalised offers, while at the same time focusing on the bottom line by lowering the cost of goods sold with a broader range of supply deals, reshaping some store layouts and tighter inventory control.
The shares last traded at $2.81, and have gained 14 percent over the past 12 months.