After nearly two years of testing, Wal-Mart is ready to roll out extensive scheduling changes for its hourly workforce in hopes of improving the daily experience for employees.

For many workers, low wages aren’t the only downside of a job in retail. Many have to cope with shifts that can change on short notice in response to store traffic, making it difficult to fit in other priorities like school and childcare.

But those practices have been changing over the past year, as companies respond to increasing public awareness around the impact on workers’ lives of “just-in-time” scheduling. The changes come as states and cities across the country pursue proposals that would require companies to provide more predictable hours for workers, following first-in-the-nation legislation for retail workers in San Francisco.

Right now, most of Wal-Mart’s 4,655 U.S. stores operate on a system of “open shifts,” where managers schedule workers within the times the employees said they’re available. By the end of the year, Walmart says it plans to make two options available: Fixed shifts, which guarantee the same weekly hours for as long as a year, and flex shifts, which allow associates to build their own schedules from the hours available, in roughly two-and-a-half-week increments.

Fixed shifts would be offered first to employees with the longest tenure, and then on a first-come-first-serve basis as new shifts become available. The company is working on an app that would allow workers to choose and update their schedules on their smartphones.

“The more visibility and information you’re able to show associates about what’s out there, you’re able to make it their choice,” says Wal-Mart spokesman Kory Lundberg. And more features might be coming in the future, like the ability to split shifts in smaller increments. “I think everything is on the table, in figuring out how to get people in the store working when people are shopping. There are a lot of things we’re looking at to see how we can make it work.”

The company has been testing the new system, which is built on commercial software modified for Wal-Mart’s use, at stores in Van Buren, Arkansas, and Wichita, Kansas for two years. And Wal-Mart thinks the changes will help its bottom line as well: Early results showed an 11 percent decline in absenteeism and a 14 percent drop in staff turnover.

The new set of policies include some things activists have been demanding for several years.

In 2013, a campaign project of the United Food and Commercial Workers Union called OUR Walmart had sent the company a letter asking for more advance notice of schedules, more consistency, greater access to full-time work, and a process to allow employees to bid on shifts based on their seniority.

Last year, along with a round of wage increases, the company announced a new system that allows workers to volunteer for more hours and switch shifts. While the policy doesn’t entitle workers to a fuller schedule, Lundberg says the flexibility allowed many workers to cobble together 40 hours nonetheless.

The move follows several improvements meant to increase worker retention and performance: Wage increases that will bring the base rate up to $10 an hour and a new training system for helping workers advance into higher-level positions.