Statistical Process Control (SPC) charts are tools used in quality control to monitor and analyze the stability of a process over time. This study evaluates the effectiveness of eight individual Western Electric rules, also known as WECO rules, and the various combinations of these rules with Shewhart rule (or WECO rule 1) to SPC charts. As more rules are added to a process control scheme with Rule 1, there is a trade-off: a higher false out-of-control signal rate but an increase in sensitivity, that is the ability of a specified process control scheme to capture a true out-of-control signal. This research explores the effectiveness of process control schemes by investigating a plan’s run length, that is to analyze the theoretical probability of observing a control signal for a specified control plan via Markov chains method and simulations in R.
","abstract_html":"<p>Statistical Process Control (SPC) charts are tools used in quality control to monitor and analyze the stability of a process over time. This study evaluates the effectiveness of eight individual Western Electric rules, also known as WECO rules, and the various combinations of these rules with Shewhart rule (or WECO rule 1) to SPC charts. As more rules are added to a process control scheme with Rule 1, there is a trade-off: a higher false out-of-control signal rate but an increase in sensitivity, that is the ability of a specified process control scheme to capture a true out-of-control signal. This research explores the effectiveness of process control schemes by investigating a plan’s run length, that is to analyze the theoretical probability of observing a control signal for a specified control plan via Markov chains method and simulations in R.</p>","abstract_has_math":false,"creators":["Ngo, Tran B"],"institution":null,"degree_name":"Master of Science - Mathematical Sciences","degree_level":"Thesis","degree_discipline":"Mathematics and Statistics","degree_department":null,"school":null,"contributors":["Robert Henderson","Gregory Miller","Jacob Turner"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-08-01T07:00:00Z","date_published":"2025-08-01T07:00:00Z","updated_at":"2026-07-24T04:30:49Z","subjects":["Process control","Western Electric Company Rules","WECO Rules","False signal rate","Sensitivity rate","Statistical process control (SPC) charts","Applied Mathematics","Applied Statistics"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarworks.sfasu.edu/etds/634","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Robert Henderson","Gregory Miller","Jacob Turner"]},{"key":"dc:creator","label":"Author","values":["Ngo, Tran B"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2025-08-08T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mathematics and Statistics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science - Mathematical Sciences"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Process control","Western Electric Company Rules","WECO Rules","False signal rate","Sensitivity rate","Statistical process control (SPC) charts","Applied Mathematics","Applied Statistics"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarworks.sfasu.edu/etds/634"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Statistical Process Control (SPC) charts are tools used in quality control to monitor and analyze the stability of a process over time. This study evaluates the effectiveness of eight individual Western Electric rules, also known as WECO rules, and the various combinations of these rules with Shewhart rule (or WECO rule 1) to SPC charts. As more rules are added to a process control scheme with Rule 1, there is a trade-off: a higher false out-of-control signal rate but an increase in sensitivity, that is the ability of a specified process control scheme to capture a true out-of-control signal. This research explores the effectiveness of process control schemes by investigating a plan’s run length, that is to analyze the theoretical probability of observing a control signal for a specified control plan via Markov chains method and simulations in R.
"]},{"key":"dc:title","label":"Title","values":["SIMULTANEOUS APPLICATION OF MULTIPLE PROCESS CONTROL RULES"]}]}],"canonical_facts":{"dc:contributor":["Robert Henderson","Gregory Miller","Jacob Turner"],"dc:creator":["Ngo, Tran B"],"dc:date.available":["2025-08-08T07:00:00Z"],"dc:description.abstract":["Statistical Process Control (SPC) charts are tools used in quality control to monitor and analyze the stability of a process over time. This study evaluates the effectiveness of eight individual Western Electric rules, also known as WECO rules, and the various combinations of these rules with Shewhart rule (or WECO rule 1) to SPC charts. As more rules are added to a process control scheme with Rule 1, there is a trade-off: a higher false out-of-control signal rate but an increase in sensitivity, that is the ability of a specified process control scheme to capture a true out-of-control signal. This research explores the effectiveness of process control schemes by investigating a plan’s run length, that is to analyze the theoretical probability of observing a control signal for a specified control plan via Markov chains method and simulations in R.
"],"dc:identifier":["https://scholarworks.sfasu.edu/etds/634"],"dc:subject":["Process control","Western Electric Company Rules","WECO Rules","False signal rate","Sensitivity rate","Statistical process control (SPC) charts","Applied Mathematics","Applied Statistics"],"dc:title":["SIMULTANEOUS APPLICATION OF MULTIPLE PROCESS CONTROL RULES"],"thesis:degree_discipline":["Mathematics and Statistics"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science - Mathematical Sciences"]},"updated_at":"2026-07-24T04:30:49Z"}