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Answer the questions by selecting the appropriate options. Note that some questions are single-answer multiple choice, and others require you to select a specific number of options. When you've answered a single-answer question, you will be told whether it is 'correct' or 'wrong'. When you attempt a multiple-answer question, the fraction shown represents the number of items which have been correctly selected plus those correctly left unselected. Keep trying until you get a fraction which equals 1 (e.g. 4/4, 5/5, 6/6 etc). When you attempt a short answer question type in your answer in the box (you can ask for a hint if you get stuck).
A flow system has an output rate of 25 items per day, and a throughput time of 12 days. How much work-in-progress will be in the system?
12
24
25
250
300
400
The stages in a serial system of four linked processses have reliabilities of 95%, 99%, 83% and 97.5% respectively. Assuming the stages are statistically independent, what is the reliability of the overall system?
96%
86%
76%
67%
A seven-stage serial process (of independent stages) where each stage is 90% reliable…
...will fail 90% of the time
...will fail just over half of the time
... will fail 70% of the time
This diagram reflects the idea that...
THE CAPACITY IS NOT HOW MUCH THE SYSTEM CAN HOLD… …..BUT HOW MANY DEFECTS ARE MADE IN THE PROCESS
THE CAPABILITY OF A SYSTEM IS DETERMINED BY THE EXTENT OF THE VARIATION OF THE SYSTEM
THE CAPACITY IS NOT HOW MUCH THE SYSTEM CAN HOLD… …..BUT HOW MUCH STUFF CAN TRAVEL THROUGH
WORK IN PROGRESS = THROUGHPUT TIME x PRODUCTION RATE
The diagram shows a serial (unbuffered) system with the daily capacities of the individual stages. What is the capacity of the overall system?
2
8
7
9
31
43
The "Rule of the Bottleneck" can be described as:
Only reduced capacity at the bottleneck increases the speed and reliability of a system; increasing the capacity of the bottleneck is a waste of time.
Sometimes a bottleneck increases the speed and dependability of a system.
Systems which contain a bottleneck are intrinsically inefficient.
Only action at the bottleneck increases the productive capacity of a system, so increasing the capacity of a non-bottleneck is a waste of time.
Goldratt's Theory of Constraints emerged from a production planning approach called...
Optimised Production Technology
Materials Requirements Planning
Goal Programming
Manufacturing Resource Planning
Enterprise Resource Planning
SAP R3
Goldratt's key ideas are described in a novel called...
'The Touchdown'
'The Tubby Scout'
'The Goal'
'Out of the Crisis'
'Jonah Saves the Day'
The key ideas of OPT are often referred to as...
Drum - Silo - Chain
Order - Chain - Delivery
Think - Plan - Do
Drum - Buffer - Rope
Aim - Shoot - Run
The basic principal of just-in-time is...
don't forecast beyond the planning horizon
don't think about problems until they occur.
don't process an order until the customer has paid.
don't make anything unless it’s needed by the next process.
This photo is from the Toyota Kentucky plant: what does the blanked-out sign actually say?
No participation - no profit!!
No waste - no mistakes!!
No quality - no job!!
No kanban - no production!!
No learning - no promotion!!
The Japanese word which captures the idea of workers being able to stop the line if they think anything is wrong is:
Heijunka
Andon
Jidoka
Kanban
Poke Yoke
Monozukuri
In queuing analysis, the ratio of the arrival rate to the service rate is called...
...the efficiency
...the expected delay
...the utilisation
...the density
In a single-server queue, if the arrival rate is 10 an hour and the service rate is 15 an hour, what is a good estimate for the number of people in the queue (including the person being served)?
1
2
3
4
5
6
Which of the following is not one of Maister's (1984) laws of queuing?
Unexplained waiting is longer than explained waiting.
Unfamiliar waits seem longer than familiar ones.
Physically uncomfortable waits feel longer than comfortable waits.
Unfair waiting is longer than fair waiting.
Pre-service waiting feels longer than in-service waiting.
OPERATIONS MANAGEMENT REVISION QUIZ 
