Lecture 04: Process design & Assignment introduction

Question 1

Value Stream Mapping (3)

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Answer 1

A lean managent technique that, ..

Level 1
maps main processes from suppliers to customers

Level 2
helps analyzing the current state of material and information flow

Level 3
helps designing a desired future state

Question 2

Show an example of a VSM (value stream map)! (3)

Answer 2

Order Level:
Customer (order, forcast)
→ Production Planning (orders)
→ Supplier (raw materials)

Logistcs Level:
production / shipping scedule

Production Level:
producing
→ assembly
→ packing
→ shipping

Question 3

What are the benefits of a VSM (Value Stream Mapping)? (3)

Answer 3

• Simple tool with standard icons
• Generates transparency
• Helps in finding improvement opportunities

Question 4

What are the limitations of a value stream map? (3)

Answer 4

• Static method / takes a snapshot of processes
• Require efforts to create and update VSM
• Limited value for high-variety production settings

Question 5

Name 4 typical process data included in a value stream map!

Answer 5

• Cycle Time (C/T)
• Changeover Time (C/O)
• Batch size
• Scrap / Rework / Defect Rate

Question 6

Process-Box includes .. (2)

Answer 6

Changeover Time
time needed to setup machine for a different product type (C/O)

Uptime
how long is the machine operational without rebooting or maintenance

• on-demand machine uptime, process capacity
• as opposed to down-time / system is not working

Question 7

Name four recommendations for value stream mapping! (4)

Answer 7

1. Focus on one product family only in current-state drawing
2. Follow the product’s way from the end to the beginning (upstream) and door-to-door first
3. Map the whole value stream by yourself
4. Bring pen, pencil, and a stopwatch

Question 8

What are the elements for a good value stream? (3)

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Answer 8

• Limited waste
  (especially overproduction)
• Synchronized takt time
  (with customer takt)
• Continuous flow

Question 9

What is a bottleneck?

What happens if a bottleneck is removed? (2)

Answer 9

• Capacity constraint
• Another will appear

Question 10

Do you have a bottleneck if line balancing meets market takt time?

Answer 10

No

Question 11

How is the takt time defined historically and within lean production? (2)

Answer 11

Takt time = Production time available / required units produced

• Average time between the production of two consecutive units to meet market demand.
• consecutive - describes things or events that follow one after another in order, without interruption or gaps

Question 12

What is cycle time?

Answer 12

Time between the production of two consecutive units in a process (~netto)

Question 13

What is order lead time?

Answer 13

Time it takes from order placement to product delivery

Question 14

What is throughput time?

Answer 14

Time it takes from the start of processing an order on the shopfloor till it is finished

Question 15

What is line balancing

Answer 15

Leveling each process cycle time to be equal or faster than market takt time.

Question 16

How is the takt time calculated? (Formular)

Answer 16

Takt time = Production time available / required units produced

Question 17

Production Lead Time (~ brutto)

Answer 17

Sum of all process times

Question 18

How is the total Value-Add Time (~ netto) calculated?

Answer 18

Sum of all cycle times

Question 19

How is the Proportional Value-Add Time calculated? (3)

Answer 19

Proportional Value-Add Time = Total value add time / (Total value add time + Total production lead time)

Value-Add Time (~ netto)

• duration within a production process during which actual value is added to a product or service, typically through activities that directly contribute to meeting customer requirements.
• It excludes non-value-added activities such as waiting, transportation, and inspection.

Production Lead Time (~ brutto)

• total time required to complete a product from the initiation of its production process (starting with the first step) to its final delivery or completion.
• It encompasses all activities, including value-adding and non-value-adding, in the production process.

Question 20

What is process mining?

Answer 20

Business analytic software

Question 21

What can process mining bring? (2)

Answer 21

Transparency in business processes, helps to compare, .,

• actual activities that occur with planned processes
• event log with the design world as designed in the process model → Helps spotting bottlenecks and when and where they are occuring

Question 22

What information does the Event log provide? (3)

Answer 22

Information about which product was produced when and where

Question 23

What is a layout?

Answer 23

Floor plan

Question 24

What granularities of a floor plan do exist? Explain! (2)

Answer 24

Macro layout
shows how buildings and departments relate to each other

Micro layout
shows how production equipment, storage and transport, and open space are organized

Question 25

What is a functional layout doing?

Name two benefits and drawbacks of functional layouts! (3)

Answer 25

Organizes similar processes in the same area.

Benefit

• Allows the creation of centers of expertise.
• Less vulnerable to machine breakdowns.

Drawback

• Hinders flow and, thereby, reduces productive due to large buffers.
• Leads to lower resource utilization.
  (Utilization - measure of how fully and productively something is being used)

Question 26

What does a product layout do?

Name two benefit and limitations of product layouts! (4)

Answer 26

Linear setup of process steps, for standardized products.

Benefits

• Simplifies training and control
• Reduced buffers

Limits

• Repetitive work
• Vulnerable to machine breakdowns

Question 27

When is fixed position layout used?

Answer 27

With heavy, fragile, and difficult to move products.

Question 28

Show the product-process matrix: (5)

Answer 28

Dimensions

• Volume →
• Flow ↓

Scope

• Fixed Position Layout
• Functional Layout
• Product Layout