Google‘s plans to test its smartphone concept ‘Project Ara’ has been postponed due to the difficulty the company is facing with mass production.

Initially, the ‘Project Ara’ modular phone was due to be trialled in Puerto Rico this year but now it has been pushed forward to 2016 at a new location in the US.

The smartphones are expected to have components that can be replaced and upgraded separately through a hardware marketplace like app store, with the company initially planning to commence selling of the new device post testing this year.

In a series of tweets, the team told followers that "#Project Ara isn’t going anywhere", but said it had been set back by "Lots of iterations… more than we thought".

The cancellation of the testing is expected to be a major setback for Google’s Advanced Technology and Projects group (ATAP).

The group is developing new mobile devices, software and services within two years time span after which the projects are either killed, moved to other parts of Google, or created as a separate entity, reported The Wall Street Journal.