Professional Maintenance Systems is a San Diego-based janitorial company that provides commercial cleaning, day porter services, and specialised cleaning for life science and healthcare facilities. As California's largest woman-owned janitorial provider, the company has operated for over 40 years and holds CIMS green building certification. They prioritise management, staff training, and measurable results to deliver reliable service. If you work with businesses needing professional commercial cleaning support, PMS would be a natural referral partner.