Process performance Data
Initial Report (1st Day)
Scenario 0
The first two weeks has been spent analyzing the operations at Mario’s. For last two weeks, the tables had a very high utilization of 97 percent and the waiting time ranged between 11 to 12 minutes.
Customers / Total / BalkedGroup of 2 / 70 / 3
Group of 4 / 106 / 37
Avg. Wait Time(Min) / 11.67
Avg. Queue Length / 3.21
Service Facility / Utilization (%) / Costs/day ($)
Tables for 4 / 99.56 / 28
Tables for 2 / 0.00 / 0
Wait Staff / 75.28 / 200
Kitchen Staff / 56.39 / 160
Manual Ovens / 75.28 / 80
Misc./day ($) / 630
Total Cost / day ($) / 2,021
Sales ($) / 3,075
Profit ($) / 1,054
Lost Sales ($) / 1,155
Service Facility / Quantity
Tables for 4 / 14
Tables for 2 / - 0 +
Wait Staff / - 4 +
Kitchen Staff / - 2 +
Process of Waiting Line for Customer
Activity / Time (Peak)Customer Enters at / 6.30 p.m.
Customer waits till / 6.41 p.m.
Customer Seated at / 6.42 p.m.
Order Taken at / 6.44 p.m.
Order Processed at / 6.46 p.m.
Order to Kitchen at / 6.48 p.m.
Customer Served at / 7.01 p.m.
Customer eats Pizza till / 7.19 p.m.
Billing and Payment at / 7.21 p.m.
Customer Exits at / 7.23 p.m.
Capacity Report
Service Facility / Capacity / Mean (Min.) / Std. Deviation (Min) / Costs/day ($)Tables for 4 / 14 / 28
Tables for 2 / 0 / 0
Wait Staff / 4 / 8.00 / 2.12 / 200
Kitchen Staff / 2 / 3.00 / 1.00 / 160
Manual Ovens / 4 / 8.00 / 0.90 / 80
Costs
Description / Cost/dayTables (for 4 and 2) (Maintenance Costs) / $2 per table
Wait Staff (Wages) / $50 per waiter
Kitchen Staff (Wages) / $80 per person
Manual Ovens (Operating Cost) / $20 per oven
Miscellaneous Cost
Restaurant Managers (Wages) / $90
Maintenance Staff (2) (Wages) / $45 per person
Lighting, Air-conditioning, and other Equipment / $150
Rent
Mario’s Restaurant / $300
Costs
Cost per Pizza / $2.25
Price per Pizza / $7.50
Order per Group of 4 / 4
Order per Group of 2 / 2
Formula for Utilization,
Utilization = {t/(T*n)}*100
Where t = time for which a particular server is utilized
T = total time for which the restaurant is open
n = quantity of a particular server
New Simulation Process
Scenario 1 (Week 1-2)
Changed process has following Configuration:
Service Facility / QuantityTables for 4 / 11
Tables for 2 / - 6 +
Wait Staff / - 7 +
Kitchen Staff / - 5 +
Impact of new configuration on business of Pizza
Customers / Total / BalkedGroup of 2 / 71 / 14
Group of 4 / 105 / 9
Avg. Wait Time(Min) / 6.46
Avg. Queue Length / 2.55
Service Facility / Utilization (%) / Costs/day ($)
Tables for 4 / 95.04 / 22
Tables for 2 / 90.32 / 12
Wait Staff / 48.29 / 350
Kitchen Staff / 25.22 / 400
Manual Ovens / 84.72 / 80
Misc./day ($) / 630
Total Cost / day ($) / 2,615
Sales ($) / 3,735
Profit ($) / 1,120
Lost Sales ($) / 480
Scenario 2 (Week 3-4)
Second Simulation process has following configuration:
Service Facility / QuantityTables for 4 / 10
Tables for 2 / - 8 +
Wait Staff / - 4 +
Kitchen Staff / - 4 +
Impact of new configuration on business of Pizza
You have spent the first two weeks analyzing the operations at Mario’s. You realize that for last two weeks, the tables had a very high utilization of 97 percent and the waiting time ranged between 11 to 12 minutes.
Customers / Total / BalkedGroup of 2 / 71 / 3
Group of 4 / 105 / 13
Avg. Wait Time(Min) / 5.53
Avg. Queue Length / 2.67
Service Facility / Utilization (%) / Costs/day ($)
Tables for 4 / 95.61 / 20
Tables for 2 / 90.21 / 16
Wait Staff / 88.61 / 200
Kitchen Staff / 33.06 / 320
Manual Ovens / 88.61 / 80
Misc./day ($) / 630
Total Cost / day ($) / 2,400
Sales ($) / 3,780
Profit ($) / 1,380
Lost Sales ($) / 435
Capacity Report
Service Facility / Capacity / Mean (Min.) / Std. Deviation (Min) / Costs/day ($)Tables for 4 / 10 / 20
Tables for 2 / 8 / 16
Wait Staff / 4 / 8.00 / 2.12 / 200
Kitchen Staff / 4 / 3.00 / 1.00 / 320
Manual Ovens / 4 / 8.00 / 0.90 / 80
Process of Waiting Line for Customer
At the beginning, the tables for four showed the highest utilization at 99.56 percent and 37 groups of four balked or left the restaurant without being served. To tackle this problem, I changed the distribution of tables and established a priority rule. This was a good decision. After I made my decision, the utilization of tables for four changed to 95.61 percent and tables for two changed to 90.21 percent.
13 groups of four and 3 groups of two balked or left the restaurant without being served. The average waiting time changed to 5.53 minutes and the average queue length changed to 2.67. It earned a profit of $1,380, but lost sales worth $435.
However this is not an optimum solution as the wait staff and the kitchen staffs are underutilized. There are also lost sales worth $435. Making changes in the wait staff or kitchen staff capacity did not have any significant impact on the waiting time. In such a case Mario may end up with too much or too less capacity which may add to Mario operating costs. Mario is not exactly thrilled with this decision. However, he is willing to with hold judgment until the end of two months.
Scenario3(Week 5-6)
Menu point, an automatic order taking system, and a convey or oven by Plax Ovens may help to bring the process under control.
After purchasing menu point,
Capacity Report
Service Facility / Capacity / Mean (Min.) / Std. Deviation (Min) / Costs/day ($)Tables for 4 / 10 / 20
Tables for 2 / 8 / 16
Wait Staff / 4 / 8.00 / 1.75 / 200
Kitchen Staff / 2 / 3.00 / 1.00 / 160
Manual Ovens / 1 / 15.00 / 0.90 / 20
Plax Ovens / 1 / 4.00 / 0.05 / 30
Customers / Total / Balked / Lost Sales ($)
Group of 2 / 70 / 3 / 45
Group of 4 / 106 / 10 / 300
Avg. Wait Time(Min) / 5.11
Avg. Queue Length / 2.30
Misc./day ($) / 630
Total Cost / day ($) / 2,242
Sales ($) / 3,885
Profit ($) / 1,644
Lost Sales ($) / 345
Bought Menu Point / Yes
I decided to buy the conveyor oven from Plax. This was a good decision since the mean processing time of the manual ovens has increased to 15 minutes. The mean processing time of the conveyer oven is 4.00 minutes and will have a significant impact on the waiting time. However, you decided to keep one of the manual ovens operational. At a high processing time of 15 minutes, this oven is adding to operating costs and could form bottleneck in the future.
I also decided to buy the MenuPoint System. This reduced the mean processing time of the waiters from 13 minutes to 8 minutes and had a significant impact on the waiting time. The average waiting time in the restaurant is now 5.11 minutes and the average queue length is 2.3.
10 groups of four and 3 groups of two balked or left the restaurant without being served. Mario is very happy with the profit of $1,644. He is also pleased that the lost sales amount reduced to $345 and is certain that I am capable of running the restaurant.
Scenario4 (Week 7-8)
Mario has planned to implement one Plax Oven and One Menu point without any need of manual oven.
Service Facility / QuantityTables for 4 / 10
Tables for 2 / - 8 +
Wait Staff / - 4 +
Kitchen Staff / - 2 +
Customers / Total / Balked
Group of 2 / 100 / 16
Group of 4 / 140 / 31
Avg. Wait Time(Min) / 4.93
Avg. Queue Length / 2.88
Service Facility / Utilization (%) / Costs/day ($)
Tables for 4 / 95.11 / 20
Tables for 2 / 92.71 / 16
Wait Staff / 71.20 / 300
Kitchen Staff / 80.14 / 160
Plax Ovens / 53.33 / 60
Misc./day ($) / 630
Total Cost / day ($) / 2,545
Sales ($) / 4,530
Profit ($) / 1,985
Lost Sales ($) / 1,170
Process of Waiting Line for Customer
Activity / Time (Peak)Customer Enters at / 6.30 p.m.
Customer waits till / 6.35 p.m.
Customer Seated at / 6.36 p.m.
Order Taken at / 6.37 p.m.
Order Processed at / 6.40 p.m.
Order to Kitchen at / 6.44 p.m.
Customer Served at / 6.51 p.m.
Customer eats Pizza till / 7.09 p.m.
Billing and Payment at / 7.11 p.m.
Customer Exits at / 7.13 p.m.
Capacity Report
Service Facility / Capacity / Mean (Min.) / Std. Deviation (Min) / Costs/day ($)Tables for 4 / 10 / 20
Tables for 2 / 8 / 16
Wait Staff / 6 / 8.00 / 1.75 / 300
Kitchen Staff / 2 / 3.00 / 1.00 / 160
Manual Ovens / 0 / 15.00 / 0.90 / 20
Plax Ovens / 2 / 4.00 / 0.05 / 30
Costs
Description / Cost/dayTables (for 4 and 2) (Maintenance Costs) / $2 per table
Wait Staff (Wages) / $50 per waiter
Kitchen Staff (Wages) / $80 per person
Manual Ovens (Operating Cost) / $20 per oven
Miscellaneous Cost
Restaurant Managers (Wages) / $90
Maintenance Staff (2) (Wages) / $45 per person
Lighting, Air-conditioning, and other Equipment / $150
Rent
Mario’s Restaurant / $300
Cream Puffs / $250
Cost for maintaining the take out counter ( including wages of 2 attendants as $70 per attendant) / $200
Costs
Cost per Pizza / $2.25
Price per Pizza / $7.50
Order per Group of 4 / 4
Order per Group of 2 / 2
To meet the increase in demand you decided to rent Cream Puffs, the next-door bakery. This was a good decision as the capacity at Mario’s has increased by seven tables for four and four tables for two. The average waiting time is now 3.45 minutes and the average queue length is 2.68.
Mario earned a profit of $2,061, but lost sales worth $720. Mario is pleased with this decision. He likes the flexibility that new place gives the restaurant. He is sure he has made a good decision by giving the responsibility of the restaurant to you.
Week 7-8
Capacity Report
Service Facility / Capacity / Utilization / Mean (Min.) / Std. Deviation (Min) / Costs/day ($)Tables for 4 / 17 / 82.40 / 34
Tables for 2 / 12 / 78.33 / 24
Wait Staff / 5 / 93.94 / 8.00 / 1.75 / 250
Kitchen Staff / 3 / 58.61 / 3.00 / 1.00 / 240
Manual Ovens / 0 / 0.00 / 15.00 / 0.90 / 0
Plax Ovens / 2 / 58.61 / 4.00 / 0.05 / 60
Customers
Customers / Total / Balked / Lost SalesGroup of 2 / 92 / 6 / 90
Group of 4 / 147 / 21 / 630
Avg. Wait Time(Min) / 3.45
Avg. Queue Length / 2.68
Costs
Misc./day ($) / 880Total Cost / day ($) / 3,009
Sales ($) / 5,070
Profit ($) / 2,081
Cream Puffs / Yes
Mario’s Take out / No
I have seen how service facilities and their utilization affected the waiting lines at Mario’s. Waiting lines form when customers arrive at a faster rate than the service system can provide.
Maintaining waiting lines, is not about shorter or longer queues, but about maintaining balance between the demand for service and the capacity of the system to provide the service.
As a manager I should be concerned about operating characteristics such as the line length, the number of customers in the system, the waiting time spent in the line, the total time spent in the system, and the service facility utilization. An effective way of analyzing a waiting line problem is to relate these characteristics to their costs.
A long queue at favorite restaurant is enough to annoy even the most patient customer. Several such experiences may result in loss of a customer, which translates into loss in sales.