Elevator System and Operational System - Systems Design - Case Study | SYST 210, Study notes of Systems Engineering

Download Elevator System and Operational System - Systems Design - Case Study | SYST 210 and more Study notes Systems Engineering in PDF only on Docsity!  1995 - 9, Dennis Buede 1 Elevator System Case Study1 Operational System Dennis Buede Department of Systems Engineering and Operations Research George Mason University Fairfax, VA 22030-4444 703 993 1727 dbuede@gmu.edu 1 This case study is based upon an M.S. project completed by Cathleen Brown and homework assignments completed by many students.  1995 - 9, Dennis Buede 2 Table of Contents 1.0 INTRODUCTION 3 2.0 ELEVATOR SYSTEM OPERATIONAL CONCEPT 3 2.1 Vision 3 2.2 Mission Requirements 3 2.3 Operational Phase Scenarios 4 3.0 ELEVATOR SYSTEM EXTERNAL SYSTEMS DIAGRAMS FOR OPERATIONAL PHASE 7 4.0 ELEVATOR SYSTEM ORIGINATING REQUIREMENTS DOCUMENT 8 4.1 System Overview 8 4.2 Applicable Documents 8 4.3 Operational Phase Requirements. 9 5.0 FUNCTIONAL ARCHITECTURE FOR OPERATIONAL PHASE 15 6.0 PHYSICAL ARCHITECTURE FOR THE OPERATIONAL PHASE 22 7.0 OPERATIONAL ARCHITECTURE FOR THE OPERATIONAL PHASE 23  1995 - 9, Dennis Buede 5 Fire Alarm Signal Maint. Action Maintenance Passenger Building Elevator Personnel Exit Opportunity at nearest floor Fire alarm Passenger Elevator Entry/Exit Opportunity Signal to Extend Entry/Exit Opportunity Entry/Exit Opportunity Ending Signal Extended Entry/Exit Opportunity Maint. Action Maintenance Passenger Elevator Personnel Feedback about emergency Communication about emergency Exit Opportunity Relayed Communication Malfunction Signal Passengers Elevator Passengers’ Weight Characteristic Capacity Exceeded Signal Prolonged Exit Opportunity Passenger Elevator Building Sensed Passenger Heat Loss/Gain Elevator Heat Loss/Gain Sensed Building Heat Loss/Gain 3) Passengers are receiving transportation in the elevator system when a fire breaks out in the building; building alarm system sends signal to elevator system to stop elevator cars stop at the nearest floor, provide exit opportunity, and sound a fire alarm. Passengers leave elevator cars. Elevator cars are reactivated by special access available to maintenance personnel. 4) Passengers are entering (exiting) an elevator car when doors start to shut; passengers can stop doors from shutting and continue to enter (exit). 5) Elevator car stops functioning and sends a signal to service. Passengers in the elevator car push an emergency alarm that notifies building personnel to come and help them. Elevator maintenance personnel create an exit opportunity. 6) Too many passengers enter an elevator car and the weight of passengers in the elevator car exceeds a preset safety limit; the elevator car signals a capacity problem and provides prolonged exit opportunity until some passengers exit the car. 7) Maintain a comfortable environment in the elevator by sensing the temperature in the elevator car that is based upon heat loss/gain of the passengers and the building and then supplying the necessary heat loss/gain to keep the passengers comfortable.  1995 - 9, Dennis Buede 6 Maintenance Personnel Elevator Signal to Change to Partial Maintenance Mode Diagnosis Signals Diagnosis Responses Continue as Necessary Repairs Test Signals Test Responses Continue as Necessary Signal to Change to Full Operating Mode Elevator Building Electric Power Request Electric Power 8) A maintenance person needs to repair an individual car; the maintenance person places the elevator system in “partial maintenance” mode so that the other cars can continue to pick up passengers while the car(s) in question is (are) being diagnosed, repaired, and tested. After completion the maintenance person places the elevator system in “full operation” mode. 9) Electric power is transferred to the elevator from the building.  1995 - 9, Dennis Buede 7 3.0 Elevator System External Systems Diagrams for Operational Phase USED AT CONTEXT: NODE: TITLE: NUMBER AUTHOR PROJECT: NOTES: 1 2 3 4 5 6 7 8 9 10 DATE REV WORKING DRAFT RECOMMENDED PUBLICATION READER DATE P. 1 xElevator Case Study Dennis Buede George Mason Univ. 09/27/1999 A-1 Provide Elevator Services A0 Comm. about Emergency, Passenger Weight Characteristics, Sensed Passenger Heat Loss/Gain Relayed Info about Emergency, Electric Power, Sensed Building Heat Maint. Action, Diagnosis Signals, Repairs, Test Signals Up Service Request, Floor Request, Request to Extend Entry support Fire Alarm Signal Signal for Partial Maint. Mode, Signal for Full Op'g Mode Feedback: Service Request Recieved, Floor Request Received, Car On Way, Door Opening, Door Closing, Floor Where Stopped, About Emergency, Fire Alarm, Entry/Exit Opp'y Ending Signal, Capacity Exceeded Signal Malfunction Signal Elevator Entry/Exit Opportunity, Information about Emergency, Elevator Heat Loss/Gain Request Elevator Services A-11 Maintain Elevator Operations A-13 Provide Structural Support A-14 Passengers' Needs Emergency Messages Emergency Comm'n Passengers Elevator System Maintenance Personnel Building Repair Parts External Systems Diagram for Operational Phase Maintenance Quality Standards Government Regulations Diagnosis Response, Test Response Electrical Power Relayed Emer. Comm. Info. about Emergency Fire Alarm  1995 - 9, Dennis Buede 10 4.3.1.1.1 Requirements for inputs from passengers 4.3.1.1.1.1 The elevator system shall receive 99.99% of communications about emergencies from passengers. 4.3.1.1.1.2 The elevator system shall receive information about total passenger weight in a given car that is 90% correct. 4.3.1.1.1.3 The elevator system shall receive information about the temperature in the elevator car based upon passenger heat loss/gain that is 95% correct. 4.3.1.1.1.4 The elevator system shall receive 99.99% of calls for up and down service from all floors of the building. 4.3.1.1.1.5 The elevator system shall receive 99.99% of passenger activated floor selections in each elevator car. 4.3.1.1.1.6 The elevator system shall receive 99% of signals from the passengers to control operation of the elevator doors. 4.3.1.1.2 Requirements for inputs from maintenance personnel 4.3.1.1.2.1 The elevator system shall receive 50% of all routine maintenance actions within 1 hour. The design goal is 80% within 1 hour. 4.3.1.1.2.2 The elevator system shall receive 99.9% of all diagnosis signals. 4.3.1.1.2.3 The elevator system shall receive 50% of all repairs within 2 hours. 4.3.1.1.2.4 The elevator system shall receive 99% of all test signals. 4.3.1.1.2.5 The elevator system shall receive 99.9% of signals for the partial maintenance mode of the elevator cars. These maintenance mode signals include information about the timing, order, velocity and acceleration characteristics of each car. 4.3.1.1.2.6 The elevator system shall receive 99.9% of signals for reconfiguring the full operational mode of the elevator cars. This operational mode signal includes information about the timing, order, velocity and acceleration characteristics of the cars. 4.3.1.1.3 Requirements for inputs from building housing the elevator 4.3.1.1.3.1 The elevator system shall receive 99.99% of all relayed information about emergencies. 4.3.1.1.3.2 The elevator system shall receive electric power 99.99% of the time. 4.3.1.1.3.3 The elevator system shall receive information on the temperature in the building that is 90% correct. 4.3.1.1.3.4 The elevator system shall receive 99.999% of all fire alarm signals sounded in the building. 4.3.1.2 Output Requirements. 4.3.1.2.1 Requirements for outputs to passengers 4.3.1.2.1.1 Entry/exit opportunities.  1995 - 9, Dennis Buede 11 4.3.1.2.1.1.1 The elevator system shall open and close automatically 99.99% of the time upon arrival at each selected floor. 4.3.1.2.1.1.2 The elevator system shall have an average wait for service (time interval between elevators) of less than 35 seconds. The design goal is 27 seconds. 4.3.1.2.1.1.3 The elevator system shall provide alternate exit(s) in the event that the primary exit is inoperable. 4.3.1.2.1.1.4 The elevator system shall have an average passenger transit time in the elevator car of no larger than 90 seconds. The design goal is 60 seconds. 4.3.1.2.1.1.5 The elevator system shall come to rest within 0.5 inch of the landing at each floor. 4.3.1.2.1.1.6 The elevator system shall provide service even during periods of maintenance. 4.3.1.2.1.1.7 The elevator system shall provide rates of acceleration and deceleration that are within the standard limits of comfort to passengers. 4.3.1.2.1.2 The elevator system shall provide information about an emergency 99.99% of the time. 4.3.1.2.1.3 The elevator system shall provide air ventilation, heating, and air- conditioning that meets customer expectations 99.99% of the time. 4.3.1.2.1.4 Feedback to the passengers and prospective passengers. 4.3.1.2.1.4.1 The elevator system shall provide indications 99.9% of the time to let a prospective passenger know that he/she has successfully called the elevator. 4.3.1.2.1.4.2 The elevator system shall provide indications 99.9% of the time to let a passenger know that he/she has successfully input a floor request to the elevator. 4.3.1.2.1.4.3 The elevator system shall provide indications 99.9% of the time to let prospective passengers know which floor the elevator is currently servicing and which direction the elevator is heading. 4.3.1.2.1.4.4 The elevator system shall provide indications 99% of the time to let passengers and prospective passengers know that the elevator door is opening. 4.3.1.2.1.4.5 The elevator system shall provide indications 99% of the time to let passengers and prospective passengers know that the elevator door is closing. 4.3.1.2.1.4.6 The elevator system shall provide indications 99.9% of the time to let passengers know at which floor the elevator has stopped. 4.3.1.2.1.4.7 The elevator system shall provide indications 99.99% of the time to let passengers know that their input about an emergency has been received. 4.3.1.2.1.5 The elevator system shall provide fire alarm signals 99.99% of the time that a fire alarm has sounded in the building. 4.3.1.2.1.6 The elevator system shall provide indications 99.9% of the time to passengers and prospective passengers that an entry/exit opportunity is ending. 4.3.1.2.1.7 The elevator system shall provide indications 99.9% of the time to the passengers when the elevator capacity is exceeded. 4.3.1.2.2 Requirements for outputs to maintenance personnel  1995 - 9, Dennis Buede 12 4.3.1.2.2.1 The elevator system shall provide diagnostic responses that are 99% correct based upon the diagnostic signals. 4.3.1.2.2.2 The elevator system shall provide test responses that are 99.9% correct based upon the test signals. 4.3.1.2.2.3 The elevator system shall provide a malfunction signal 99% of the time that a malfunction is detected. 4.3.1.2.3 Requirements for outputs to the building. The elevator system shall provide emergency communications 99.99% of the time that a passenger is providing emergency communication signals. 4.3.1.3 External Interface Requirements. 4.3.1.3.1 Electric Power. The elevator system shall receive power from the building's main power supply via ANSI standard connections. 4.3.1.3.2 Emergency Communications Response The elevator system shall connect to an ANSI standard phone system in the building. 4.3.1.4 Functional Requirements. 4.3.1.4.1 The elevator system shall accept passenger requests and provide feedback.. 4.3.1.4.2 The elevator system shall move passengers between floors safely and comfortably. 4.3.1.4.3 The elevator system shall control elevator cars efficiently. 4.3.1.4.4 The elevator system shall enable effective maintenance and servicing. 4.3.2 System-wide & Technology Requirements. 4.3.2.1 Technology Requirements - none 4.3.2.2 Suitability Requirements 4.3.2.2.1 "Government Regulations". 4.3.2.2.1.1 The elevator system shall support all relevant fire and safety codes in effect. 4.3.2.2.1.2 The elevator system shall strictly adhere to all Federal, State, and Local government regulations. 4.3.2.2.1.3 The elevator system shall comply with the Americans with Disabilities Act. 4.3.2.2.2 The elevator system shall have an MTBF of greater than 1 year. The design goal is 1.5 years. Failure is defined to be a complete inability to carry passengers. 4.3.2.2.3 The elevator system shall have an MTTR of less than 8 hours. The design goal is 4 hours. Repair means the system is returned to full operating capacity. 4.3.2.2.4 The elevator system shall operate continuously between the range of 64-80 degrees Fahrenheit. 4.3.2.2.5 The elevator system shall be generic enough to be placed in a range of similar buildings across the United States.  1995 - 9, Dennis Buede 15 5.0 Functional Architecture for Operational Phase USED AT CONTEXT: NODE: TITLE NUMBER AUTHOR PROJECT: NOTES: 1 2 3 4 5 6 7 8 9 10 DATE REV WORKING DRAFT RECOMMENDED PUBLICATION READER DATE P. Top 2 xElevator Case Study Dennis Buede George Mason Univ. 09/27/1999 Provide Elevator ServicesA-0 PROVIDE ELEVATOR SERVICES A0 Up Service Request, Floor Request, Request to Extend Entry support PURPOSE: To define boundary and architectures for the Operational Phase of the Elevator System VIEWPOINT: Up & Down, Ltd. Systems Engineering Team Comm. about Emergency, Passenger Weight Characteristics, Sensed Passenger Heat Loss/Gain Relayed Info about Emergency, Electric Power, Sensed Building Heat Maint. Action, Diagnosis Signals, Repairs, Test Signals Floor Request Received, Car On Way, Door Opening, Door Closing, Floor Where Stopped, About Emergency; Fire Alarm; Entry/Exit Opp'y Ending Signal; Capacity Exceeded Signal Malfunction Signal Elevator Entry/Exit Opportunity, Information about Emergency, Elevator Heat Loss/Gain Emergency Comm'n Diagnosis Response, Test Response Fire Alarm Signal Signal for Partial Maint. Mode, Signal for Full Op'g Mode Elevator System  1995 - 9, Dennis Buede 16 USED AT CONTEXT: NODE: TITLE NUMBER AUTHOR PROJECT: NOTES: 1 2 3 4 5 6 7 8 9 10 DATE REV WORKING DRAFT RECOMMENDED PUBLICATION READER DATE P. A-0 3 xElevator Case Study Dennis Buede George Mason Univ. 09/29/1999 PROVIDE ELEVATOR SERVICEA0 ACCEPT PASSENGER REQUESTS & PROVIDE FEEDBACK A1 CONTROL ELEVATOR CARS A2 MOVE PASSENGERS BETWEEN FLOORS A3 ENABLE EFFECTIVE MAINTENANCE & SERVICING A4 Digitized Passenger Requests Assignments for Elevator Cars Elevator Position & Direction Sensed Malfunctions, Diagnosis & Test Responses Temporary Modificatin to Elevator Configuration Electric Power Electric Power Up Service Request, Floor Request, Request to Extend Entry support Relayed Info about Emergency, Electric Power, Sensed Building Heat Comm. about Emergency, Passenger Weight Characteristics, Sensed Passenger Heat Loss/Gain Maint. Action, Diagnosis Signals, Repairs, Test Signals Diagnosis Response, Test Response Malfunction Signal Feedback: Service Request Recieved, Floor Request Received, Car On Way, Door Opening, Door Closing, Floor Where Stopped, About Emergency; Fire Alarm; Entry/Exit Opp'y Ending Signal; Capacity Exceeded Signal Emergency Comm'n Elevator Entry/Exit Opportunity, Information about Emergency, Elevator Heat Loss/Gain Fire Alarm SignalSignal for Partial Maint. Mode, Signal for Full Op'g Mode Request to Extend Entry support Up Service Request, Floor Request Feedback: Service Request Recieved, Floor Request Received, Car On Way, Door Opening, Door Closing, Floor Where Stopped, About Emergency; Fire Alarm Entry/Exit Opp'y Ending Signal; Capacity Exceeded Signal Operating Mode Diagnosis Signals, Maint. Action, Repairs, Test Signals  1995 - 9, Dennis Buede 17 USED AT CONTEXT: NODE: TITLE NUMBER AUTHOR PROJECT: NOTES: 1 2 3 4 5 6 7 8 9 10 DATE: REV: WORKING DRAFT RECOMMENDED PUBLICATION READER DATE P. A0 4 xElevator Case Study Dennis Buede George Mason Univ. 09/29/1999 ACCEPT PASSENGER REQUESTS & PROVIDE FEEDBACA1 Elevator Position & Direction I2 Sensed Malfunctions, Diagnosis & Test Responses O3 SUPPORT WAITING PASSENGERS A11 SUPPORT RIDING PASSENGERS A12 SUPPORT PASSENGERS IN EMERGENCY A13 Request for Floor Request for Elevator Service Digitized Passenger Requests O2 Sensed Floor-based Malfunctions, Diagnosis & Test Responses Sensed Car-based Malfunctions, Diagnosis & Test Responses Sensed Emergency Malfunctions, Diagnosis & Test Responses Digitized Emergency Requests Digitiazed Requests from Riding Passengers Digitized Requests from Waiting Passengers Up Service Request, Floor Request Feedback: Service Request Recieved, Floor Request Received, Car On Way, Door Opening, Door Closing, Floor Where Stopped, About Emergency; Operating Mode Feedback: Service Request Recieved, Car On Way, Door Opeininn, Door Closing Feedback: Floor Request Received, Door Opeininn, Door Closing, Floor Where Stopped Feedback About Emergency Diagnosis Signals, Maint. Action, Repairs, Test Signals  1995 - 9, Dennis Buede 20 USED AT CONTEXT: NODE: TITLE NUMBER AUTHOR PROJECT: NOTES: 1 2 3 4 5 6 7 8 9 10 DATE REV WORKING DRAFT RECOMMENDED PUBLICATION READER DATE P. A0 8 xElevator Case Study Dennis Buede George Mason Univ. 09/29/1999 ENABLE EFFECTIVE MAINTENANCE & SERVICINA4 Sensed Malfunctions, Diagnosis & Test Responses I1 REPORT MALFUNCTIONS & STATUS A41 RESPOND TO MAINTENANCE EMPLOYEES A42 Diagnosis Response, Test Response Malfunction Signal Operating Mode Temporary Modificatin to Elevator Configuration Maint. Action, Diagnosis Signals, Repairs, Test Signals Diagnosis Signals, Maint. Action, Repairs, Test Signals  1995 - 9, Dennis Buede 21  1995 - 9, Dennis Buede 22 6.0 Physical Architecture for the Operational Phase Elevator Call Announcement Destination Control Door Control Emergency Phone Car Control Passenger Interface Component Hardware Software Elevator Control Component Cab Interior Door Ventilation & Lighting Car Shaft Structure Exit Controls Floor Stop Leveling Shaft Switch Car/Shaft Normal Drive/Brake Emergency Braking Drive/Brake Elevator Cars Component Maintenance & Service Component Elevator System  1995 - 9, Dennis Buede 25 The following set of FFBDs provide the behavioral model for the operational architecture. Ref. AND AND 1.0 Accept Passenger Requests & P... 2.0 Control Elevator Cars 3.0 Move Passengers Between Floors 4.0 Enable Effective Maintenance & Servicing Ref. Ref. AND AND 1.1 Support Waiting Passengers 1.2 Supporting Riding Passengers 1.3 Support Passengers in Emergency Ref.  1995 - 9, Dennis Buede 26