Chinese assemblers of iPhones and iPads now work a reduced average of 60 hours each week, according to the update report released Tuesday by Washington-based Fair Labor Association (FLA).

The marked improvements in Apple's supply chain environment have so far impacted some 150,000 workers that were deployed in three giant assembly facilities maintained by Foxconn in Chengdu, Guanlan and Longhua. On its latest progress report, the FLA detailed substantial changes on the notoriously sub-standard working conditions endured by Apple factory workers.

A statement from the tech titan has confirmed that from March 2012, Apple workers that were detailed for 60-hours per week assignment have shrunk from about 11 per cent to three per cent in July this year.

The company said it intends to spread the positive adjustments to a workforce of some 700,000 that were tasked to put together sleek and shiny devices that already delivered more than $100 billion of cash reserves for Apple.

FLA also noted on its report that Apple has agreed to trim its Chinese workforce's working hours to 49 hours each week, which is the mandated work hours embodied in China's labour laws.

Target date of full compliance would be July 2013, according to the FLA report.

The labour added that for the goal to be realised within the self-imposed timeframe, Apple needs to apply more pressure on Foxconn officials to implement concrete measures that would underpin the work environment reforms.

Among the most basic needs at the moment is for Foxconn to ramp up its recruitment activity and build up housing facilities that would accommodate the hundreds of thousands of Chinese workers flocking to assembly plants that were contracted by Apple.

Majority of these workers were migrants from China's rural areas, the FLA said.

The adjustments were in line with Apple's aim of upping the standard of its supply chain environment while at the same time maintain its production timeline, which becomes more hectic in the last quarter and first quarter of a given year, the same time that Apple normally issues its hotly anticipated new products or upgrades.

The same report also outlined 195 work condition improvements that pushed by the FLA following its assessment tours on Foxconn facilities in early 2011.

Another 165 improvements have been set for completion by July 2013, 89 of which have been rolled out successfully, the FLA report said.

However, "some of the most challenging action items - such as compliance with Chinese labour law regarding hours of work - are yet to come," the international labour advocacy group was quoted by The Associated Press (AP) as saying on its report.

But the FLA assured at the same time that it "will continue to engage with Apple and Foxconn to monitor and verify progress.

FLA was contracted by Apple to revamp the alleged horrendous working conditions of Apple's Chinese workers that were made to put together high-tech gadgets, which ironically were designed to make life easier for consumers.

The FLA report came out as Apple gears up for what were speculated as its planned back-to-back launches for the new iPhone 5 and iPad Mini - a smaller version of its hit tablet computer. The launches spark fears that Apple contractors could again extend the working hours of its production lines to meet strict deadlines.