The assailants shot Baljeet Singh (45) dead and when Beena (38) came to save him, they stabbed her multiple times, injuring her severely, police said.
On hearing the gun shots, passersby rushed to the factory, but the assailants fled from the spot, they said.
Beena has been admitted to a private hospital, they said, adding that footage of CCTV cameras installed in the factory premises would be viewed to nab the culprits.
Money-related issues were likely to be the cause behind the incident, they said.