Table of Contents
Lecture 1 - Design and planning of production ....................................................................................... 2
Lecture 2- The lean toolbox..................................................................................................................... 6
Lecture 3 – How to manage resources when implementing lean? ....................................................... 14
Lecture 4- Basic process types of manufacturing.................................................................................. 19
Lecture 5 – Part 1. Batch size and Lean manufacturing ....................................................................... 26
Lecture 5 part 2 – Pull production ......................................................................................................... 29
Lecture 5 part 3- Scheduling.................................................................................................................. 33
Lecture 6 – Cellular manufacturing ....................................................................................................... 38
Lecture 7 – Line balancing .................................................................................................................... 44
,Lecture 1 - Design and planning of production
Why should we plan?
Because we can influence and need to machine Machine Idle time, product Waiting time, and
machine Changeover time with the sequence of production
› The company need to optimize these times. How?
By changing the batch size and understanding the
sequence of production
- The real added value to the customer is the processing
time.
Traditional companies try to maximize the use of machines and
reduce their idle time. Why?
- Because it costs a lot of money
However, if you increase the use of machine time, that means you
increase the batch time which in turn increases the product
waiting time.
- The larger the batch size the lower the machine idle time. However, this comes at
the expense of the product waiting time.
- Combine similar products (batching): less setups, more efficient. But: longer
waiting time for product.
- Earliest due date: no batching, less waiting time, but: more setups, less efficient
Examples of changeover:
› Light after dark paint
› Thick after thin steel bending
› Regain concentration after a disturbance.
Taiichi ohno: scheduling ( you do not have to plan the production) is waste- it
does not add value to the customer.
- Lean = avoid waste!!
o Reducing any type of waste that does not add any value to the
customer.
By doing so, you end up focusing on processing.
Eliminating them completing them is not possible but they can be reduced so you
can increase the value to the customer.
A definition of Lean
Lean production is an integrated socio-technical system whose main objective is to eliminate
waste by concurrently reducing or minimizing supplier, customer, and internal variability’
,3 keys points on this definition:
1. It does not only contemplate techniques but also human resources.
a. Interaction between people and technology in workplaces
2. Lean does not improve profitability (it does but indirectly), the main aim is to reduce
any source of variability.
› The interaction of social and technical factors creates the conditions for successful (or
unsuccessful) organizational performance.
Lean philosophy
Lean means being able to follow 5 different principles.
1. Identify Value: 7+ 1 wastes
To identify value, you need to identify what is non value to the
customer and eliminate it. Sources that need to be eliminated
(DOWNTIME)
- Defects
o Strive for quality
- Overproduction
o Not producing more than necessary of
producing in advance (future is uncertain)
- Waiting
o The challenge of lean is being able to find the balance between maximizing the
time a machine is being used while minimizing the waiting time of a product.
o How? By reducing the variability
- Not using all available human potential
o Process improvement is a bottom up process in Lean. You want employees to
come up with the ideas and to do so, they need to be empowered.
- Transport
o Moving products from A to B to C etc. You want to remove the movements as
any extra movement means extra stocks are being added = higher variability.
- Inventory (The root of all evil)
o Why? Is not only because you have unsold
inventory.
Having safety stock means hiding
operations/process problems but as soon as you
decrease inventory levels, not only means having
less stock but the hidden problems now come
outside.
- Motion
o Not transporting resources but motion is moving employees around.
- Extra processing
o Only perform the activities that are seen as value adding to the customer.
, Variability is the root of all evil
Inventory is then being used as a buffer to cover for all the variability issues.
› Processing times, Quality, Customer orders, Production sequence, Setup-times, …
› Inventory is just a symptom
› To handle variability, we need to buffer:
▪ Products (inventory)
▪ Capacity (overcapacity)
▪ Time (lead time)
▪ Buffers impede our stable, predictable, efficient flow
› Variability might be a choice or prerequisite!!
▪ Offer different products
▪ Provide meaningful jobs
▪ Be agile
› If you want to reduce inventory, you need to first be able to reduce variability.
2. Map the value stream
You need to gain an understanding of what is actually happening in your process.
- You start with activities, followed by the flow of information and then you track time
and the availability for each of the steps.
- It is also important to understand how much inventory you have between each of the
activities.
- You need to understand as well how much time you use to add value (processing time)
and how much time the material takes from each of the steps.
In this case, you spend 258 hours to add only 8 hours of value to the customer ( A lot of
wasted time)
Lecture 1 - Design and planning of production ....................................................................................... 2
Lecture 2- The lean toolbox..................................................................................................................... 6
Lecture 3 – How to manage resources when implementing lean? ....................................................... 14
Lecture 4- Basic process types of manufacturing.................................................................................. 19
Lecture 5 – Part 1. Batch size and Lean manufacturing ....................................................................... 26
Lecture 5 part 2 – Pull production ......................................................................................................... 29
Lecture 5 part 3- Scheduling.................................................................................................................. 33
Lecture 6 – Cellular manufacturing ....................................................................................................... 38
Lecture 7 – Line balancing .................................................................................................................... 44
,Lecture 1 - Design and planning of production
Why should we plan?
Because we can influence and need to machine Machine Idle time, product Waiting time, and
machine Changeover time with the sequence of production
› The company need to optimize these times. How?
By changing the batch size and understanding the
sequence of production
- The real added value to the customer is the processing
time.
Traditional companies try to maximize the use of machines and
reduce their idle time. Why?
- Because it costs a lot of money
However, if you increase the use of machine time, that means you
increase the batch time which in turn increases the product
waiting time.
- The larger the batch size the lower the machine idle time. However, this comes at
the expense of the product waiting time.
- Combine similar products (batching): less setups, more efficient. But: longer
waiting time for product.
- Earliest due date: no batching, less waiting time, but: more setups, less efficient
Examples of changeover:
› Light after dark paint
› Thick after thin steel bending
› Regain concentration after a disturbance.
Taiichi ohno: scheduling ( you do not have to plan the production) is waste- it
does not add value to the customer.
- Lean = avoid waste!!
o Reducing any type of waste that does not add any value to the
customer.
By doing so, you end up focusing on processing.
Eliminating them completing them is not possible but they can be reduced so you
can increase the value to the customer.
A definition of Lean
Lean production is an integrated socio-technical system whose main objective is to eliminate
waste by concurrently reducing or minimizing supplier, customer, and internal variability’
,3 keys points on this definition:
1. It does not only contemplate techniques but also human resources.
a. Interaction between people and technology in workplaces
2. Lean does not improve profitability (it does but indirectly), the main aim is to reduce
any source of variability.
› The interaction of social and technical factors creates the conditions for successful (or
unsuccessful) organizational performance.
Lean philosophy
Lean means being able to follow 5 different principles.
1. Identify Value: 7+ 1 wastes
To identify value, you need to identify what is non value to the
customer and eliminate it. Sources that need to be eliminated
(DOWNTIME)
- Defects
o Strive for quality
- Overproduction
o Not producing more than necessary of
producing in advance (future is uncertain)
- Waiting
o The challenge of lean is being able to find the balance between maximizing the
time a machine is being used while minimizing the waiting time of a product.
o How? By reducing the variability
- Not using all available human potential
o Process improvement is a bottom up process in Lean. You want employees to
come up with the ideas and to do so, they need to be empowered.
- Transport
o Moving products from A to B to C etc. You want to remove the movements as
any extra movement means extra stocks are being added = higher variability.
- Inventory (The root of all evil)
o Why? Is not only because you have unsold
inventory.
Having safety stock means hiding
operations/process problems but as soon as you
decrease inventory levels, not only means having
less stock but the hidden problems now come
outside.
- Motion
o Not transporting resources but motion is moving employees around.
- Extra processing
o Only perform the activities that are seen as value adding to the customer.
, Variability is the root of all evil
Inventory is then being used as a buffer to cover for all the variability issues.
› Processing times, Quality, Customer orders, Production sequence, Setup-times, …
› Inventory is just a symptom
› To handle variability, we need to buffer:
▪ Products (inventory)
▪ Capacity (overcapacity)
▪ Time (lead time)
▪ Buffers impede our stable, predictable, efficient flow
› Variability might be a choice or prerequisite!!
▪ Offer different products
▪ Provide meaningful jobs
▪ Be agile
› If you want to reduce inventory, you need to first be able to reduce variability.
2. Map the value stream
You need to gain an understanding of what is actually happening in your process.
- You start with activities, followed by the flow of information and then you track time
and the availability for each of the steps.
- It is also important to understand how much inventory you have between each of the
activities.
- You need to understand as well how much time you use to add value (processing time)
and how much time the material takes from each of the steps.
In this case, you spend 258 hours to add only 8 hours of value to the customer ( A lot of
wasted time)
