North American Industry Classification System (NAICS) Codes   • PESystems is both a large and small business  NAICS    Description  333314    Optical Instrument and Lens Manufacturing (Small Business)   334515    Instrument Manufacturing for Measuring and Testing Electrical and Electrical Signals   517110    Wired Telecommunications Carriers (under 1500 personel)   541330    Engineering Services  541511    Custom Computer Programming Services  541512    Computer Systems Design Services  541513    Computer Facilities Management Services  541519    Other Computer Related Services  541611  Administrative Management And General Management Consulting Services  541712    Research And Development In The Physical, Engineering and Life Sciences (small business under 500 personnel)  561210    Facilities Support Services