SCM 300 Exam 2 Davila Questions and
Answers
Goal of waiting line management - ANS-Balance the cost paid by the customers (time)
with the cost paid by the company (money paid to maintain the system)
Parts of a waiting line system - ANS-1. Input Source - This is the population of people
that might want service
2. Waiting Line - The area in which customers wait for service
3. Service Facility - The area in which customers actually receive service
4 Managerial Considerations in Queues - ANS-1) Customers - How many are there?
How quickly are they arriving?
2) The Waiting Lines - What types of lines? How many lines?
3) Employees - Who's working in the system? How many? Skill level and speed?
4) Service Facilities - How effective and efficient is the process? Tools?
Queue - ANS-Line
Channel - ANS-Line; here it often refers to the number of lines available at each step
Phase - ANS-A single step in a process
Infinite population of customers - ANS-The number of possible customers that may
come into the store is very high (or unlimited). When a customer enters the system, the
odds of another entering the system are not impacted in any significant manner.
Finite population of customers - ANS-The number of customers is limited. Example: If
you have a bus company that has 10 busses, then your company's repair shop has a
finite population of 10 busses. If 1 bus is in the shop only 9 others are left in the
population. The odds of a 2nd bus entering the system decline.
Arrival (λ) rates: define and calculate - ANS-Number of customers arriving / unit of time
Service (μ) rates: define and calculate - ANS-Number of customers helped / unit of time
Service utilization factor (ρ) - ANS-Percentage of time worker is busy. ρ=λ/μ
Average number of customers in the line (nl) - ANS-nl = ρ[ λ / (μ-λ) ]
Average amount of time a customer waits in the line (tl) - ANS-tl = ρ[ 1 / (μ-λ) ]
, Average number of customers in the system (ns) - ANS-ns = λ / (μ-λ)
Average amount of time a customer spends in the system (ts) - ANS-1 / (μ-λ)
Probability there are "n" customers in the system (Pn) - ANS-P(n) = (1-ρ)ρ^n
Probability the System is Empty (P0) - ANS-P(0) = 1-ρ
Balking - ANS-When a potential customer sees the line but never joins the line because
they think it looks too long and/or too slow
Reneging - ANS-When a customer joins the line, gets frustrated and leaves the line
Jockeying (same as Line jumping) - ANS-Moving from one line to another
Wholesalers - ANS-These organizations purchase goods from manufacturers. Typically,
they purchase an assortment of goods from many manufacturers, thus a retail company
could purchase all of their electronics from a single wholesaler versus having to
purchase from each individual manufacturer
Drop Shippers - ANS-A drop shipper is not really a source of supply, but rather an
organization that ties manufacturers and/or wholesalers directly to consumers. Drop
shippers never actually possess the product, they simply take orders which are fulfilled
by another party
Chargebacks - ANS-These are effectively penalties charged by retail organizations to
their suppliers/vendors for any number of minor and major supply chain offenses. The
goal here is to motivate vendor compliance in the areas of on-time shipments, shipment
accuracy, product quality, incorrect packaging, label errors, etc.
Vendor-managed inventory (VMI) - ANS-An arrangement where retailers allow vendors
to monitor in-store inventories, initiate orders/shipments to the store when inventories
are low, and also bring the items into the store and onto the shelf.
Last Mile - ANS-The portion of the supply chain between the final inventory holding
facility and the end consumer
4 Types of Retail ownership - ANS-Independent retailers, chains, franchises, and
cooperatives
Planogram - ANS-A map of where every product goes on a retail store shelf
Store Layout considerations - ANS-Customer flow; consider entrance and exit points
Answers
Goal of waiting line management - ANS-Balance the cost paid by the customers (time)
with the cost paid by the company (money paid to maintain the system)
Parts of a waiting line system - ANS-1. Input Source - This is the population of people
that might want service
2. Waiting Line - The area in which customers wait for service
3. Service Facility - The area in which customers actually receive service
4 Managerial Considerations in Queues - ANS-1) Customers - How many are there?
How quickly are they arriving?
2) The Waiting Lines - What types of lines? How many lines?
3) Employees - Who's working in the system? How many? Skill level and speed?
4) Service Facilities - How effective and efficient is the process? Tools?
Queue - ANS-Line
Channel - ANS-Line; here it often refers to the number of lines available at each step
Phase - ANS-A single step in a process
Infinite population of customers - ANS-The number of possible customers that may
come into the store is very high (or unlimited). When a customer enters the system, the
odds of another entering the system are not impacted in any significant manner.
Finite population of customers - ANS-The number of customers is limited. Example: If
you have a bus company that has 10 busses, then your company's repair shop has a
finite population of 10 busses. If 1 bus is in the shop only 9 others are left in the
population. The odds of a 2nd bus entering the system decline.
Arrival (λ) rates: define and calculate - ANS-Number of customers arriving / unit of time
Service (μ) rates: define and calculate - ANS-Number of customers helped / unit of time
Service utilization factor (ρ) - ANS-Percentage of time worker is busy. ρ=λ/μ
Average number of customers in the line (nl) - ANS-nl = ρ[ λ / (μ-λ) ]
Average amount of time a customer waits in the line (tl) - ANS-tl = ρ[ 1 / (μ-λ) ]
, Average number of customers in the system (ns) - ANS-ns = λ / (μ-λ)
Average amount of time a customer spends in the system (ts) - ANS-1 / (μ-λ)
Probability there are "n" customers in the system (Pn) - ANS-P(n) = (1-ρ)ρ^n
Probability the System is Empty (P0) - ANS-P(0) = 1-ρ
Balking - ANS-When a potential customer sees the line but never joins the line because
they think it looks too long and/or too slow
Reneging - ANS-When a customer joins the line, gets frustrated and leaves the line
Jockeying (same as Line jumping) - ANS-Moving from one line to another
Wholesalers - ANS-These organizations purchase goods from manufacturers. Typically,
they purchase an assortment of goods from many manufacturers, thus a retail company
could purchase all of their electronics from a single wholesaler versus having to
purchase from each individual manufacturer
Drop Shippers - ANS-A drop shipper is not really a source of supply, but rather an
organization that ties manufacturers and/or wholesalers directly to consumers. Drop
shippers never actually possess the product, they simply take orders which are fulfilled
by another party
Chargebacks - ANS-These are effectively penalties charged by retail organizations to
their suppliers/vendors for any number of minor and major supply chain offenses. The
goal here is to motivate vendor compliance in the areas of on-time shipments, shipment
accuracy, product quality, incorrect packaging, label errors, etc.
Vendor-managed inventory (VMI) - ANS-An arrangement where retailers allow vendors
to monitor in-store inventories, initiate orders/shipments to the store when inventories
are low, and also bring the items into the store and onto the shelf.
Last Mile - ANS-The portion of the supply chain between the final inventory holding
facility and the end consumer
4 Types of Retail ownership - ANS-Independent retailers, chains, franchises, and
cooperatives
Planogram - ANS-A map of where every product goes on a retail store shelf
Store Layout considerations - ANS-Customer flow; consider entrance and exit points
