Lecture 9 - Demand-Driven Approaches

Question 1

What is a Kanban system

Answer 1

a workflow management method

• production can only commence upstream if in possession of a Kanban card, issued by downstream operations
• pull control system
  –> Work items are pulled through the system as capacity becomes available, rather than being pushed through all at once.

Question 2

How is Kanban linked to JIT, and Lean

Answer 2

*Kanban underpins Just In Time Systems
–> building block

• Lean production emphasises all of JIT’s concepts

Question 2

Goal of Kanban

Answer 2

*improve efficiency, because of continuous flow

*limit work in progress and subsequent bottlenecks, because of pull system

Question 3

Two principles of JIT

Answer 3

• producing nothing until it is needed

*produce precisely what is needed, when it is needed

Question 4

How are these principles applied

Answer 4

these are applied in internal operations, but also across extended operations

e.g. in-bound supply channels and outbound distribution channels

Question 5

Overview of Lean production

Answer 5

• focus on creating customer value by eliminating waste

Question 6

Key principles in lean

Answer 6

1. Products designed to enhance value for customer, in their perspective
2. Each step in production/operations must add value for the customer
3. Process should flow efficiently to customer without storage, or delays
4. Pull process
   –> produce what customers need when they need it
5. ‘lean philosophy’ - Environment must strive to perfect the process
   –> continual reviews, and striving for learning & improvement

Question 7

Benefits and drawbacks of lean production

Answer 7

Benefits
* demand pull implementation increases productivity
–> ensures optimal capacity utilisation (no bottlenecks)
–> also increases focus on customer (greater service)

*increased quality
–> more checks, less defects

*more flexibility by minimising WIP

• less waste

*buffer stock

Drawbacks
* require MRP control

*complex and expensive to implement (training, technology)
–> high variety in products may make it a complex procedure

• focus on cost may compromise other things
  –> employee morale, quality
• heavy dependence on suppliers being reliable, and minimal disruptions
• no buffer stock

Question 8

What is TOC

Answer 8

Theory of Constraints

• management system that identifies and addresses bottlenecks in systems

*ensures maximum continuous throughput

Question 9

What is a bottleneck

What can cause it

Answer 9

*a constraint or limit on capacity

• caused by any resource type
  –> lack of skilled personnel, limited availability of materials, machine limits

Question 10

What are the five focussing steps of TOC

Answer 10

1. Identify constraint
2. Exploit constraint
   –> optimise current capacity
3. Subordinate to the constraint
   –> align other processes and activities to support the constraint
4. Elevate constraint
   –> exploiting is short term, overall aim is to improve or remove bottleneck
   (expanding capacity, increases employee training)
5. Prevent inertia
   –> identify new bottlenecks

then back to step 1 (loop)

Question 11

What is DBR

Answer 11

Drum Buffer Rope Scheduling (DBR)

• attempts to maximise the use of the constraint by ensuring work is released at the proper time

therefore, the constraint is never starved and never overloaded (max efficiency)

Question 12

Explain the Drum Buffer Rope Scheduling

Answer 12

Drum = processing capability of the constraint

Rope = transmits info from drum to inform system to release more work

Buffer = inventories strategically placed to protect constraint

all combine to form a plant scheduling system