P ROCESS A NALYSIS P ROFESSOR D AVID G ILLEN (U NIVERSITY OF B RITISH C OLUMBIA ) & P ROFESSOR B ENNY M ANTIN (U NIVERSITY OF W ATERLOO ) Istanbul Technical University Logistic Management in Air Transport Air Transportation Management Module 2-3 M.Sc. Program 15-16 December 2014
UNDERSTANDING PROCESSES 2
W ITH A BANKED SCHEDULE , MINIMUM CONNECT TIMES DRIVE TURNAROUND TIMES – NOT GROUND OPERATIONS Ground Operations – Required Time for a Turnaround ( Carriers – 737-300) Cater Weight and Extend jetway and (15 min) Balance open door (2 min) Inside (1 min) Boarding Deplane 41-46 min (10 min) (13 min) Close door and jetway Clean cabin (1 min) (10-15 min) Close cargo Arrival door Dispatch (1 min) (2 min) (4 min) Ramp (Outside) Prearrival Fuel (10-15 min) Equipment Departure Set Up (2 Min) Ground power A/C 33-43 bin door min (3 min) Unload/load bags and cargo (20-30 min) Opportunities To Compress Ground Operations’ Turnaround Times 3
B UT , WITH A CONTINUOUS SCHEDULE , GROUND OPERATIONS DRIVES TURNAROUND TIME , AND THUS AIRPLANE / CREW UTILIZATION Ground Operations – Required Time for a Turnaround ( Southwest – 737-300) Weight and Extend jetway and Balance Cater open door (1-2 min) Inside (13-16 min) (<1 min) Deplane Cleaning 21-31 min (6 min) (2-5 min) Boarding Close door (9-13 min) and jetway (<1 min) Close cargo Arrival door (<1 min) (2-7 min) Ramp (Outside) Prearrival Unload/load bags and cargo (18-21 min) Equipment Departure Set Up (1-2 Min) Ground power A/C Fuel bin door (6-11 min) 23-32 (<2 min) min The LCCs Have Engineered Rapid Turnaround Processes emulated on short haul routes by network carriers 4
A IRCRAFT TURNAROUND AT AIRPORTS : • Activities: – Passengers disembark – Unload luggage and freight – Load data – Clean – Fuel… • Southwest says that if its boarding time increased by 10 minutes per flight, it would need 40 more planes at a cost of $40 million each to run the same number of flights it does currently!!! 5
A IRCRAFT TURNAROUND AT AIRPORTS : • Passengers boarding is the longest activity. In the mid-60s it took 20/minute, today 9/minute • Have you ever wondered whether there is a better way for boarding? • Air Canada: back to front • United Airlines: window first • America West: reverse pyramid • WestJet: random 6
M ATHEMATICIAN DEVISES WAY TO BOARD AIRPLANES FASTER A Chinese mathematician is touting a new way to get people onto commercial airline flights faster. Dr Tie-Qiao Tang, along with a small team of researchers, has suggested that airlines should assign seating after evaluating each passenger on several variables. " Each passenger has their own individual properties . For example, each passenger's luggage has a different attribution and thus has different influences on boarding behavior; the time that the passenger's ticket is checked at the gate is different; the time that the passenger deals with his or her carried luggage is different; seat conflicts have different effects on the passenger. Each passenger has a different optimal speed, maximum speed and safe distance." Basically, passengers are evaluated by how fast they can board the plane, and then are assigned a seat . The researchers compared their method to two others; the free-for-all , where passengers board in any order they like, and assigned seating . According to Tang, "overtaking, queue-jumping, seat conflict congestions and jams may occur under the first two boarding strategies," but doesn't happen with Tang's proposed method. And to boot, the third method is the fastest , according to the study. The only problem with the method is that it would require airlines to keep detailed profile information on their customers , like average boarding speed. Last year, Jason Steffen, from the Fermilab Center for Particle Astrophysics, designed a system where passengers line up in a "very specific" order and then board. His method also proved faster than getting on a plane in groups or in a back-to-front order. CBC November 13, 2012 You can find the paper at : http://www.sciencedirect.com/science/article/pii/S0968090X11001574 7
http://leeds-faculty.colorado.edu/vandenbr/projects/boarding/boarding.htm 8
T HE F LYING C ARPET BY R OB W ALLACE 9
L EARNING O BJECTIVES • Understand the following concepts: Flow Time Capacity Rate Bottleneck Flow Time Capacity Rate • Tool: Process Analysis – Process mapping – Capacity analysis (also called bottleneck analysis) • Applications – McDonald’s make -to-order system – Kristen’s Cookie Company 10
P ROCESSES • What occurs during a transformation process? – Processing – Waiting – Storage Transformation Inputs Outputs Process Raw material, people, Goods information, capital etc. Services 11
E XAMPLES OF PROCESSES wood guitars Factory metal students alumni University Distribution bulk items small parcels center Electronic Dell Computers Components • Processes can involve both goods and services. • Processes can have multiple inputs and/or multiple outputs. 12
P ROCESS E NTITIES • Flow units : The items that flow through the process – May be homogenous or heterogeneous • Activities : The transformation steps in the process – Each activity takes some time to complete • Resources : They perform the activities – Have capacities • Buffers : Storage units for flow units – May have finite size 13
P ROCESS F LOW D IAGRAM E LEMENTS Activities, tasks or operations Buffers: Queues or inventories Decision points Flow of materials • Example: Bread making Bread Packing Raw Finished Packed Making Material Bread Bread Note: If different types of breads, the bread-making and packing activities may differ for each 14
A N E XAMPLE OF A R ESERVATION P ROCESSES Uninformed Informed customers No Online agency Leave Buy? customers (Opodo) Yes Order information Opodo’s Uninformed Informed Information Airline Airline system 15
L EVEL OF D ETAIL IN P ROCESS A NALYSIS A process can be defined at an aggregate level: Transportation Tray to catering A/c catering assembly facility Food Food Trays Catered ingredients ingredients galley Transportation and assembly can contain many sub-processes: The purpose of the process analysis determines the level of detail in modeling the processes. 16
P ROCESS M EASURES • Cost • Quality measures • Time (Flow measures) • Flexibility measures • Capacity • This course focuses on capacity and flow measures . 17
P ROCESS M EASURES IN P RODUCTION AND S ERVICE Production process Service process Flow unit Materials Customers Input rate Raw material releasing rate Customers arrival rate Customers departure rate (service Output rate Finished goods output rate completion rate) Time required to turn materials into Flow time Time that a customer is being served a product Inventory Amount of work-in-process Number of customers being served Capacity Maximum output rate Maximum service completion rate 18
K EY S TEPS IN P ROCESS A NALYSIS Step 1: Determine the Purpose of the analysis Step 2: Process mapping (Define the process) • Determine the flow units • Determine the tasks (sub-processes), and the sequence of the tasks • Determine the time for each task • Determine which resources are used in each task • Determine where inventory is kept in the process • Record this through a process flow diagram (Linear flow chart, Swim-lane (deployment) flow chart, Gantt chart) Step 3 : Capacity Analysis (also called Bottleneck Analysis ) • Determine the capacity of each resource, and of the process Further analysis will be covered later during the course 19
E XAMPLE : M C D ONALD ’ S K ITCHEN • Purpose of the analysis: To determine the capacity rate of a McDonald’s restaurant Link to video • Given this purpose, we draw the process boundary around the kitchen – We do not consider customers’ queue – We do not consider meat cooking processes (we assume cooked meat is always available when needed during the make-to-order process) 20
L INEAR F LOW C HART • Flow unit: An order (each order = one burger) • Tasks and sequences • Flow time of each task Place an Toast Add Add meat Package Deliver order buns dressings patties 8s 10s 8s 6s 2s 2s • Determine which resources are used in each task • Could indicate resources along each task • Swim-lane diagram or Gantt chart may be better 21
S WIM -L ANE (D EPLOYMENT ) F LOWCHART RESOURC ACTIVITIES ES Place an Cashier order Worker1 Toast Toaster buns Add Worker 2 dressings Add meat Worker 3 patties Package Worker 4 Worker 5 Deliver 22
S WIM -L ANE F LOWCHART : M ODIFIED RESOURC ACTIVITIES ES Place an Cashier order Worker1 Toast Toaster buns Add Add meat Worker 2 Package dressings patties Worker 3 Worker 4 Worker 5 Deliver 23
G ANTT C HART RESOURCES ACTIVITIES Time Span Cashier Place an order 8 s Worker1 10s Toast buns Toaster Worker 2 Add dressings 8 s Add meat Worker 3 6s patties Worker 4 Package 2s Worker 5 Deliver 2s Time 24
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