* Industrial software platform race still wide open
* Siemens says size matters
* Siemens to partner with Amazon Web Services from next month (Releads with comments from Digital Factory CEO)
MUNICH, Dec 15 (Reuters) - Germany's Siemens sees its broad industrial base and respect for customers' data privacy as giving it the edge in a race to attract businesses to its factory software platform, rather than those of rivals.
The trains-to-turbines group is betting the future of its core industrial automation business on its MindSphere platform, which competes with General Electric's Predix and a host of others to help customers cut costs and improve productivity.
The race is still wide open, and being first to gather a critical mass of software developers and system integrators is crucial to winning customers, much as Apple's large developer community made its app store the most attractive.
"One thing is clear: Size matters," Jan Mrosik, chief executive of Siemens' 11.5 billion-euro Digital Factory division, told Reuters in an interview on Friday.
Siemens said it was targeting 1.25 million connected devices and systems by the end of its fiscal year in September, up from 1 million currently, as it expands its offering - previously focused on autos and aerospace - to cover all sectors.
MindSphere gathers data from devices, analyses the information and uses it to help customers design products faster and optimise processes.
To increase its attractiveness to developers, Siemens is partnering with Amazon Web Services (AWS), the most popular cloud provider, as of next month.
So far, it has partnered with Germany's SAP - with whom it developed the platform - and from April it will also work with Microsoft's Azure.
Mrosik said Siemens' own experience of manufacturing in fields ranging from trains to building technology to energy equipment also gave it a solid basis of customers and expertise.
Simon Jacobson, supply-chain analyst at technology research group Gartner, tended to agree.
"Where Siemens has opportunity is to leverage its domain expertise across a range of sectors," he said, although he cautioned: "This is a market thats still rapidly unravelling."
Mrosik also highlighted Siemens' policy of keeping customers' data in silos that are only visible to them as a competitive advantage. "We as Siemens technically can't look into the data of anyone," he said.
Digitally enhanced manufacturing is still in its infancy, with companies pursuing different strategies. But competition is already fierce, as evidenced by Emerson Electric's failed $29 billion bid to buy Rockwell Automation earlier this year.
Siemens is increasing research and development spending to over 5.6 billion euros this fiscal year from 5.2 billion last year, the lion's share of which will go to Digital Factory. MindSphere has a breakeven target date of 2020.
Siemens says it made 5.2 billion euros in digital revenues in the year to September. It has 23,000 in-house software developers, rivalling some of the world's biggest pure-play software companies.
"Digitalisation is starting to come together for Siemens," said Jefferies capital goods analyst Peter Reilly.
General Electric is reducing investment in its Predix industrial software platform by about $400 million this coming year to $1.2 billion, and focusing solely on its own installed base of customers for the rollout.
Under new Chief Executive John Flannery, GE as a whole is narrowing its focus and shedding businesses with around $20 billion in revenue.
GE aims to double Predix revenues to $1 billion in 2018. ($1 = 0.8485 euros) (Additional reporting by Alexander Huebner in Munich and Alwyn Scott in New York; Editing by Adrian Croft and Elaine Hardcastle)