Google-owned phone firm Motorola has announced a new project to let users customise their smartphone components.
Project Ara allows users to buy a basic phone structure and add modules such as keyboard, battery or other sensors.
Motorola has partnered with Dutch designer Dave Hakkens, who has created Phonebloks, a modular phone idea, on the project.
Experts were unsure on how big a shake-up for the mobile phone industry the customisable handsets would represent.
In a blog post, Motorola said that it had been working on the project for more than a year.
"We want to do for hardware what the Android platform has done for software - create a vibrant, third-party developer ecosystem," the firm wrote in a blog post.
"To give you the power to decide what your phone does, how it looks, where and what it's made of, how much it costs and how long you'll keep it."
The project will consist of what Motorola is calling an endoskeleton, the frame that will hold all the modules in place.
"A module can be anything from a new application processor to a new display or keyboard, an extra battery, a pulse oximeter - or something not yet thought of," the firm said.
Motorola plans to begin inviting developers to create modules in a few months time with a module developer's kit launching soon afterwards.
Motorola came across the work of Dave Hakkens, the creator of Phonebloks, while developing the project and asked him to team up with them. Phonebloks has gained much interest in recent months.
Mr Hakkens launched Phonebloks on crowd-promoting website Thunderclap and quickly amassed 950,000 supporters.
"We've done the deep technical work. Dave created a community," Motorola added in its blogpost.
Chris Green, principal technology analyst at the Davies Murphy Group consultancy, dismissed the project as a "gimmick".
"I don't see this as being a big deal. It is not responding to any particular demand and there is no real benefit to assembling your own device,
"The days of DIY IT, people building their own desktop PC, are gone due to falling costs of hardware," he said.
Ben Wood, a mobile expert from CCS Insight, is equally unsure of how mass market such a product can be.
"Creating a Lego-like phone seems on the face of it like a great idea but the commercial realities of delivering such a device are challenging. Consumers want small, attractive devices and a modular design makes this extremely difficult.
"It's a nice idea on paper but whether we'll ever see a commercial product remains to be seen. Right now it would be a great improvement if it was easier to replace batteries and screens but even that seems unlikely in the near term."