Lecture 9 - Demand-Driven Approaches Flashcards
What is a Kanban system
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.
How is Kanban linked to JIT, and Lean
*Kanban underpins Just In Time Systems
–> building block
- Lean production emphasises all of JIT’s concepts
Goal of Kanban
*improve efficiency, because of continuous flow
*limit work in progress and subsequent bottlenecks, because of pull system
Two principles of JIT
- producing nothing until it is needed
*produce precisely what is needed, when it is needed
How are these principles applied
these are applied in internal operations, but also across extended operations
e.g. in-bound supply channels and outbound distribution channels
Overview of Lean production
- focus on creating customer value by eliminating waste
Key principles in lean
- Products designed to enhance value for customer, in their perspective
- Each step in production/operations must add value for the customer
- Process should flow efficiently to customer without storage, or delays
- Pull process
–> produce what customers need when they need it - ‘lean philosophy’ - Environment must strive to perfect the process
–> continual reviews, and striving for learning & improvement
Benefits and drawbacks of lean production
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
What is TOC
Theory of Constraints
- management system that identifies and addresses bottlenecks in systems
*ensures maximum continuous throughput
What is a bottleneck
What can cause it
*a constraint or limit on capacity
- caused by any resource type
–> lack of skilled personnel, limited availability of materials, machine limits
What are the five focussing steps of TOC
- Identify constraint
- Exploit constraint
–> optimise current capacity - Subordinate to the constraint
–> align other processes and activities to support the constraint - Elevate constraint
–> exploiting is short term, overall aim is to improve or remove bottleneck
(expanding capacity, increases employee training) - Prevent inertia
–> identify new bottlenecks
then back to step 1 (loop)
What is DBR
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)
Explain the Drum Buffer Rope Scheduling
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