Microsoft has bought Seattle-based people analytics software maker VoloMetrix. The new addition will become part of an organisational analytics offering to Microsoft’s cloud service customers.

VoloMetrix uses information about employee email and calendar use to assess their individual and collective productivity. The system can also pull in data from Salesforce and other sources. By identifying employees that have too many meetings or who create excessive email traffic it can help companies manage their time resources more effectively.

According to Microsoft corporate vice president Rajesh Jha the newly acquired technology will be a strand in Microsoft’s new organisational analytics service Delve which will be unveiled for previews in October. Eventually, the service will become part of Microsoft’s cloud service Office 365.

The terms of the acquisition have not been disclosed. VoloMetrix co-founder and CEO Ryan Fuller blogged that joining Microsoft means the company can grow far more quickly. “Microsoft has a huge vision to reinvent productivity and a set of assets in Office 365 that are fundamental to how work gets done,” Fuller said.

VoluMetrix had previously raised $17 million in funding, including a $12 million cash injection in September 2014. Its enterprise clients include Boeing, Facebook, Genentech, Qualcomm, Seagate and Symantec.

Quantifying employee productivity is a new growth area with two start ups, Culture Amp and VoloMetrix, leading the field. These systems collate data about employees’ electronic calendar and email behaviour and use that data to assess people’s impact at work.

The systems can expose those who spend all their time “managing up” to senior executives or promoting themselves in status meetings, rather than working, according to Volometric founder Fuller. “You can quickly see the load senior executives are imposing, as well as the social graph of who else is affected,” said Fuller.

Cloud based people analytics will be used to understand the external and internal relationships and drive corporate decision-making, Fuller said: “Once a company understands the behaviours that correlate to success, they can measure them.”

In anticipation of opposition over privacy issues, VoloMetrix recently hired former Microsoft privacy strategist, Peter Cullen, to advise it. Reports are currently anonymous and private but individuals can see their own statistics.

Australian rival Culture Amp, used by enterprises like Airbnb, Box, Etsy, GoDaddy and Jawbone,

received $6.3 million in Series A funding from Felicis Ventures, Index Ventures and Blackbird Ventures in March 2015.