JIT

Question 1

What is “Just-in-time (JIT)”? (3)

Answer 1

producing and procuring

• the right items,
• at the right time and
• in the right amounts

Question 2

What are the key principles of Just-in-Time (JIT)? Explain them roughly! (3)

Answer 2

• One-piece flow: Moving a product through every step of the process without grouping it into a batch
• Takt time: s.o.
• Pull-based production: Products are pulled into production as needed or requested by customers (no overproduction)

Question 3

What do push and pull systems lead to?

• High / Low 🤸‍♂️ (2x4)

Answer 3

Push System lead to: Low flexibility

• High capital lockup
• High inventory
• High planning efforts

Pull System lead to: High flexibility

• Low capital lockup
• Low inventory space needed
• Low planning effor

Question 4

What is Kanban? (2)

Answer 4

• A visual and flexible workflow management / scheduling system,
• that aligns supplies with actual demand.

Question 5

Explain how Kanban works, roughly? (2)

Answer 5

Pull system

• Once a certain number of resources is consumed, the supplier receives a signal to produce/deliver a new shipment.
• Rate of demand controls the rate of production.

Visual signals

• Control signal, can be visualized with physical Kanban cards
• containing relevant information for supply (e.g., item description, item number, order date, quantity) or other signaling mechanisms

Question 6

How can you describe an ideal state of efficiency?

Answer 6

With FLOW

Question 7

What is FLOW?

Answer 7

F lexible systems
L eveled processes
O verload avoidance
W aste reduction

Question 8

How can you increase productivity? (2)

Answer 8

• Optimize the flow, material movement and streamline the process
• Synchronise the four M’s (Manpower, Machines, Materials, and Methods)

Question 9

Why are there queues (Warteschlangen)? (2)

Answer 9

• Service time > Arrival time
• Variability (in service / arrival times)

Question 10

What is Little’s Law? (3)

Answer 10

• work-in-process inventory
• WIP = Processing rate * Flow time
• a fundamental principle in queuing theory

Question 11

Name different aspects by which queuing systems can be characterized! (4)

Answer 11

Number of servers - number of service channels or resources available to serve in the queue

Queuing discipline - method or rule for selection from the queu, e.g.,

• First-in-first-out (FIFO),
• Last-in-first-out (LIFO)

Arrival sources - infinite vs limited

Queue space - infinite vs limited