Sigma is a statistical term that relates to quality.
Quality in a service organization means minimum process cycle times, high customer satisfaction ratings, timeliness and accuracy of reports, problem free service delivery, reliable processes and order fulfillment, smooth back office operations, etc. The Sigma level for an average company is measured at Four Sigma. Unsafe drinking water for 15 minutes each day. No telephone service for 10 minutes each week. Six Sigma is the ultimate goal.