(Reuters) - A Starbucks Corp SBUX.O initiative designed to improve speed and customer service has not fixed staffing shortages, according to an outside survey of company workers released on Thursday.

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The survey results from Coworker.org, which hosts online petitions, come a year after U.S. Starbucks workers used the site to protest staffing cutbacks that they warned were slowing service and hurting morale at the popular coffee chain.

Coworker.org said its poll included 184 self-identified, current U.S. Starbucks cafe workers, supervisors and managers across 33 states.

New Chief Executive Kevin Johnson launched the initiative at Starbucks, which has more than 13,000 U.S. coffee shops, with more than 150,000 workers.

In January, Starbucks said some of its busiest U.S. cafes were grappling with bottlenecks at drink pick-up stations during peak hours. Executives blamed the delays on an avalanche of mobile orders and said the backups had chased away some walk-in customers.

The company, which has reported two straight quarters of declines in U.S. traffic, reworked tasks to make them more efficient and gave managers more leeway to add staffing as part of a broad customer re-engagement program dubbed “North Star.” That effort is led by Kris Engskov, Starbucks’ president of U.S. retail, under the guidance of Johnson, who succeeded longtime CEO Howard Schultz in April.

“All of our metrics show we are moving in the opposite direction of what the survey claims,” Starbucks spokesman Reggie Borges said.

“Over the last eight months, we’ve added labor to about 15 percent of our stores and are looking to add more in the months ahead,” he said.

Despite that, 75 percent of the Starbucks workers polled by Coworker.org said their stores were not staffed to meet the goals of North Star.

Eighty-nine percent of respondents said staffing levels were still a problem in their stores in the past three months, and 62 percent said their ability to deliver the best customer service possible decreased during that time.

Mobile ordering has “added to the work load immensely, and yet again, there aren’t even enough people scheduled to share the workload,” an unnamed Starbucks partner told Coworker.org.

A Starbucks employee last year launched a Coworker.org petition, accusing the chain of “extreme” cutbacks in work hours that were crushing morale. The petition currently has more than 18,000 signatures.

Workers last year told Reuters they noticed the reduction in hours in April 2016, after Starbucks reported a deceleration in quarterly cafe sales growth.