Lean Production and Quality Cost Management: Eight Common Wastes in Factories

Keywords: Cost, waste, quality, eight major management, common lean production factories

The main means and methods for reducing on-site costs

1) Improving quality

2) Improving productivity

3) Reduce inventory

4) Shorten production line

5) Reduce machine downtime

6) Reduce space

7) Reduce production lead time

 

Quality management is not the responsibility of any department or individual, but rather the shared responsibility of all members of the company. It is important to understand that every small step should be taken into consideration in order to ensure the quality of the entire product. It is important to understand that the next step is the customer

Quality is managed, not inspected

The quality management of lean production emphasizes the prevention of non-conforming products, ensuring that no defective products occur from the perspectives of operators, machines, molds, tools, materials, and production processes

It emphasizes ensuring quality from the root

Conduct inspections in each process, emphasizing the quality awareness of employees and promptly identifying quality issues

If there is a problem with a certain process and it cannot meet the requirements of the next process, the production line will immediately stop working until the problem is solved

Usually, individuals and groups cooperate to solve problems

Consider quality issues during design

Standardization of product structure

Reduce the number of parts

Standardization of parts

Do it well the first time

All personnel participate

No need for inventory to stabilize and conceal quality issues

 

What is Quality Cost (COQ)

 

Quality cost

Pre visit cost

Appraisal cost

Loss cost

Internal loss cost

External loss cost

 

Self inspection and mutual inspection are commonly referred to as "double inspection" in work, mainly to implement autonomous management

(1) Implement self inspection and mutual inspection of processes

A. Educate and train operators, instill the importance of implementing "double inspection";

B. Regularly conduct on-site spot checks and supervise the implementation of the "double inspection";

C. Emphasize that "double inspection" is the responsibility of both parties involved when problems arise

D. Develop clear responsibility systems, implement assessments and rewards and punishments

How frontline supervisors should cooperate with the company to improve quality

a) Strong responsiveness and ability to handle quality;

b) Understand that the next process is the customer;

c) Operate according to standard specifications;

d) Conduct independent inspections in the workshop;

e) Timely reporting and notification of abnormal phenomena;

f) Proper use and maintenance of equipment, tools, and testing instruments;

g) Material control and surrounding environment organization;

h) Passionate about work, with a high sense of responsibility;

On site quality improvement and enhancement

1) The production workshop uses various indicator lights and billboards to display the normal production process

No, to improve quality and quick response ability

2) Establish a feedback mechanism for quality anomaly information

3) Work closely with quality, engineering, procurement and other departments

4) Establish a cross departmental team for quality improvement

5) Utilizing PDCA to improve and enhance quality

On site quality improvement - Seven techniques

Checklist

Layer classification method

Causal diagram

Plato

histogram

Control diagram

Scatter plot

Tools for Six Sigma

Statistical Process Control (SPC), Quality Function Deployment (QFD), Failure Mode and Effects Analysis (FMEA), Cause and Effects Matrix, British Standard, Process Capability Analysis, Multivariate Studies, Reliability Analysis, Experimental Design (DOE), Measurement Systems Analysis (MSA), Value Chain Analysis (Value Chain Analysis), KJ Methodology, Process Map, Inference Statistics)

Descriptive statistics

Fishbone chart, histogram, Plato, correlation chart, sampling test, control chart, correlation analysis, regression analysis, scatter method, analysis of variance

Full factorial experiments

Modular Design

Tolerance Design

Concept Engineering

Stage/Gate Process

SIPOC (Supplier Input Process Output Customer)

JMP

VOC

Screening studies

Hypothesis testing

Definition of waste

In the JIT production method, the meaning of waste is different from what is commonly referred to as waste in society. For JIT, any part that exceeds the minimum amount of materials, equipment, manpower, space, and time absolutely necessary to increase product value is a waste. Therefore, the waste referred to by the JIT production method not only refers to activities that do not add value, but also includes activities that use resources beyond the "absolute minimum" limit.

Various waste phenomena are common in many enterprises that have not yet implemented 5S activities, as shown in Table 1-1. In order to eliminate waste in the factory, it is necessary to first identify unreasonable areas and then find ways to solve the problem. This requires the implementation of more advanced management methods such as 5S and JIT.

Table 1-1 Five major losses of waste in enterprises that have not implemented 5S activities

Waste performance	harm
Members with disheveled appearance	Harmful to corporate image, affecting morale, prone to danger, and difficult to identify
Unreasonable equipment layout	Large number of semi-finished products, increased handling, ineffective operations
Improper equipment maintenance	Easy to cause malfunctions, increase repair costs, and affect quality
Random placement of items	Easy to mix materials, time-consuming search, and prone to becoming obsolete materials
Channel blockage	Difficulty in homework, potential danger, increased handling

Eight Common Wastes in Factories

1、 Quality defects (defective products, waste of repairs)
Any defective products result in waste of materials, machinery, labor, etc.
Early detection of defective products can easily identify the source of the defect and reduce its occurrence.
The key is to get things right the first time and achieve "zero defects"

Due to the occurrence of defective products in the factory, there is a waste of time, manpower, and material resources required for disposal, as well as the resulting losses. This type of waste specifically includes: material loss, defective products becoming waste; Loss of equipment, personnel, and working hours; The loss of additional repair, identification, and additional inspection; Sometimes it is necessary to lower prices for products, or the factory's reputation may decline due to delayed shipments.
2、 Disposal (processing waste)
Definition: Refers to unnecessary processing that is unrelated to engineering progress and processing accuracy, also known as waste of excessive processing. It mainly includes two layers of meaning: the first is redundant processing and overly precise processing, such as resource waste caused by excessive actual processing accuracy; The second is the need for extra homework time and auxiliary equipment, as well as increasing the waste of energy such as electricity, air pressure, and oil in production. In addition, it also increases the working hours for management.
Some processing programs can be omitted, replaced, reorganized, or merged.
Many times I get used to and believe that the current approach is better
3、 Waste of actions
12 types of wasted actions:
◆ Two hands idle ◆ One hand idle ◆ Incoherent pauses ◆ Too much amplitude ◆ Left and right hand exchanges ◆ Multiple walks
◆ Large turning angle ◆ Changing states during movement ◆ Unclear techniques ◆ Back extension movements ◆ Bending movements ◆ Repeating unnecessary movements

The waste of these actions results in unnecessary consumption of time and energy.
4、 Transportation (waste of handling)
Currently, many domestic enterprise managers believe that handling is necessary and not a waste. Therefore, many people turn a blind eye to waste in transportation, let alone eliminate it. From the perspective of JIT, handling is an action that does not generate additional value, and work that does not generate value is considered waste.
Can we overcome it using a "conveyor belt" method? This approach is to spend a lot of money to reduce the physical exertion of workers, but in fact, it does not rule out the waste of transportation itself.
1. Waste collection and disposal; 2. Waiting for waste; 3. Excessive waste of work in progress; 4. Space waste.
The specific manifestation of waste in transportation is the waste of actions such as placing, stacking, moving, and arranging, which leads to the waste of space required for item movement, time, and the occupation of human tools and other adverse consequences.
5、 Waste of inventory
Excessive inventory conceals problems and reduces inventory exposure issues
Lean production believes that "inventory is the source of all evil", and all improvement actions are directly or indirectly related to eliminating inventory.
① Causing unnecessary waste such as handling, stacking, placing, protective treatment, and searching, making the first in, first out operation difficult
③ Loss of interest and management expenses ④ The value of the item will decrease and become obsolete
⑤ Occupying factory space, causing redundant factories, warehouse construction, etc. ⑥ Misjudgment of equipment capacity and personnel needs
◆ The intangible losses caused by inventory are not inferior to the tangible losses mentioned above. Lean producers believe that inventory will hide problems, and "problems" are considered treasures in lean producers. If problems can be continuously discovered and solved, benefits will continue to be generated
1. Lack of management tension hinders improvement:
2. Once the inventory level is high, the adverse consequences caused by mechanical failures and defective products cannot be immediately apparent, and therefore no countermeasures will be taken.
3. Due to sufficient inventory, when problems arise, they can be topped up with inventory first, and the problem can be slowly solved or even not solved. At the very least, it is covered up, not urgent, and will not be pursued by superiors. As a result, the work performance of our department has been achieved. According to past management concepts, people believed that although inventory was not a good thing, it was necessary. JIT's view is that inventory is unnecessary, and even believes that inventory is the source of all evil. Due to a large inventory, problems such as malfunctions, defective products, absences, interruptions, planning errors, long adjustment times, inconsistent quality, and imbalanced capabilities have all been covered up.
For example, some companies may experience production line malfunctions, resulting in shutdowns or shutdowns. However, due to inventory availability, the issue of shutdowns or shutdowns caused by malfunctions is masked, which delays troubleshooting. If inventory is reduced, the above-mentioned problems can be completely exposed to the horizontal plane, and gradually these inventory wastes can be solved.
6、 Transition production (excessive manufacturing or premature waste)
TPS emphasizes "timely production".
Doing more can improve efficiency, and doing it well in advance can reduce production capacity loss (not doing it for nothing, isn't the machine still standing still?)
1. It's just that we used up the material and labor costs early, and we can't get any benefits.
2. Hide "waiting waste" and make managers ignore the occurrence and existence of waiting.
3. The backlog of work in progress invisibly lengthens the production cycle L/T, and increases the on-site workspace, unknowingly eroding our profits.
4. It becomes difficult to handle and stack waste, making it first in, first out. Manufacturing too much or too early, consuming production costs in advance, not only has no benefits, but also hides the waste caused by waiting, losing opportunities for continuous improvement. Some enterprises, due to their strong production capacity, increase their work in progress to avoid wasting production capacity, resulting in shorter product cycles, larger space, and increased waste in handling and stacking. In addition, manufacturing too much or too early can lead to large inventory levels, increased interest burden, and inevitably increased risk of depreciation.
7、 Waste of waiting
◆ Variety switching on production lines ◆ When the workload is low, there is nothing to do ◆ Often there is a shortage of materials and equipment is idle
◆ Delayed upstream process, with nothing to do downstream ◆ Equipment failure ◆ Unbalanced production line processes
◆ There is a phenomenon of uneven work and rest ◆ Manufacturing notices or design drawings have not been delivered

The waste of waiting caused by interruptions in the supply of raw materials, imbalanced operations, and improper production planning is called idle waiting. If the preparation work is not sufficient for switching between different varieties on the production line, it will inevitably lead to waste of waiting; The daily workload changes significantly, sometimes very busy, and sometimes resulting in idle personnel and equipment; There are problems with upstream processes, resulting in downstream processes having nothing to do. In addition, the existence of unequal labor and rest in production lines is also an important reason for waiting waste.
8、 Management waste
Management waste refers to the additional waste generated by managers only taking corresponding measures to remedy problems after they occur. Management waste is a problem caused by inadequate prior management. Scientific management should have considerable foresight, reasonable planning, and strengthen management, control, and feedback in the process of progress. This can greatly reduce the occurrence of management waste
How to eliminate waste of time, personnel, and management

Clarify which jobs are high value and low value

Applying the 20/80 principle

Work plan management and goal management are beneficial for time management

What is the time wasted by enterprises

1) Long production cycle time

2) Long procurement time

3) Delayed handling of abnormal situations

4) The switching time is too long when converting the production line to a MODEL

5) Machine replacement, mold replacement time too long

6) Unreasonable work plan leads to wasted time

7) The workload has changed too much, resulting in personnel and equipment being idle

8) Frequent machine idle or production line shutdown due to material shortages or delays in the previous process;

10) Machine equipment often malfunctions;

11) The production line failed to achieve balance

12) Lack of coordination among departments leads to wasted time in decision-making;

13) The waste caused by too many meetings

How to eliminate time waste

Develop specific response and solution measures based on the reasons for wasting time

Establish and improve various systems and operational processes

Establish time standards and make timely improvements and adjustments

Effectively implement (follow up, supervise)

Regular review, evaluation, and continuous improvement

The significance of eliminating personnel waste:

1) Improve work efficiency

2) Reduce labor costs

3) Reduce employee burnout and procrastination, and minimize other waste caused by it

Explore potential surplus personnel

1) How to tap into the surplus of personnel on the production line

2) How to tap into the surplus of management personnel

3) How to Explore the Process of Personnel in Functional Departments

How to eliminate waste on personnel

1) Analyze the potential surplus of personnel

A. Fixed position and personnel

B. The rationality of job settings

C. The saturation level of workload

2) Exclusion of unprofitable work

A. Clarify which tasks are not beneficial

B. Streamlining and merging workflows

3) Improve operations and equipment, increase production efficiency, and achieve less manpower

How to eliminate waste on personnel

1) Reorganize organizational structure and streamline personnel

2) Expand the scope of responsibilities and management scope

3) Full authorization

How to reduce the eight major wastes in management work

1. Idle waste where management elements cannot be effectively utilized

2. Management cost waste caused by lack of goals and plans

3. Lack of cohesion and coordination waste

4. Efficiency waste caused by inefficiency

5. Disorderly waste caused by personal preference

6. Lack of responsibility and initiative in waiting for waste

7. Dealing with waste perfunctorily

8. Waste of additional management personnel due to supervision and management

Eight common misconceptions in daily management

1. I can't control myself. I enjoy doing technical work - I'm not good at managing people

2. It's my credit. I'm used to relying on personal effort to complete tasks - working alone, not good at building

Establish an effective work network and team

3. It's mainly up to me to do it, I really don't trust it. There are no details, and I'm not good at authorizing everything at once

4. Regardless of whether it has been completed or not, although there are work goals, there is a lack of goal control

5. I like to be casual and take each step at a time. I am not good at it and am not used to making plans

6. Let's talk about it if there are any issues. Firefighting is common

7. Who can help me? I haven't received systematic management skills training and my knowledge is not enough

8. Ah Buddha, fortunately there hasn't been much change and there hasn't been any mistake

Eight common mistakes made by managers

(1) Lack of ownership and sense of responsibility, refusing to take personal responsibility

(2) The ideology of "departmentalism" is severe, focusing only on personal and departmental interests

(3) Single management approach and lack of targeted leadership

(4) Failure to train and guide subordinates effectively

(5) Character misalignment

(6) Lack of self-discipline, casual style, ignoring negative impacts

(7) Lack of tracking and monitoring of work

(8) Making mistakes in personnel and shielding people with insufficient abilities

The Eight Rules for Successful Supervisors

(1) Clear goals

(2) Do the right thing

(3) Winning through cooperation

(4) A positive mindset

(5) Communication has no limits

(6) Self proclaimed as the owner

(7) By the customer's side

(8) Pursuing Excellence

Analysis of Types of Supervisors

Forced suppression type: stubborn and conservative, excessively suppressing employees, afraid of employees threatening their status

Brotherly loyalty type: often treating employees as brothers and sisters, expressing brotherly loyalty, being emotional in work, lacking principles, and unable to play the role that supervisors should have

Coach type: both skilled and knowledgeable in management, emphasizing training for employees and team building, with a clear sense of goals, actively identifying and solving problems

Model worker: able to work steadfastly and industriously, only knowing how to do things by oneself, not managing employees, not suitable for leadership

Da Sa Ba type: unwilling to be a manager, working as a monk every day, struggling with work, lacking a sense of responsibility, adopting a policy of inaction, and living in vain

Obedient type: emphasizes absolute obedience, is loyal to superiors, and has no doubt or resistance, but will never take the initiative to do things. Obey superiors' instructions in everything, and strive for no achievements but no mistakes. Often lacks innovation and management skills

Production technology oriented: Skilled in technical business, but lacking interpersonal coordination skills, with simple work methods, often treating employees in the same way as machines

 

Lean production goals (four low and two short):

The lowest amount of waste,

The lowest inventory level,

The lowest handling capacity,

The machine failure rate is low,

The shortest lead time for production,

The shortest preparation time

Lean production is a new production method developed to meet the diverse, high-quality, low-cost, and short delivery needs of customers

 

The 7 ultimate "zero" goals pursued by lean production

Zero switching time

Zero inventory

Zero waste

Zero defects

Zero fault

Zero stagnation

Zero disaster

 

The two cores of lean production:

Firstly, eliminate all waste, cancel activities that do not add value, and achieve "cost reduction"

Secondly, quickly respond to market changes

 

Specific methods for implementing lean production JIT:

(1) The synchronization of production is achieved through "post process collection" (also known as pull type), where the post process only receives the required processed products from the previous process when needed; The previous process only produces according to the quantity and variety received

(2) The equalization of production is achieved through mixed production (simultaneous production of multiple varieties) or process balancing. In machine use, equalization is achieved through the generalization of specialized equipment and standardized operations

(3) The flexibility of production is achieved through the establishment of split unit production lines, fixed and variable production lines, and simple disassembly and assembly production lines. When the output changes, the number of workers is increased or decreased, and the production cycle is shortened to cope with market changes in the assembly line

 

Specific methods for achieving lean production

Consolidate True Knowledge and Collaborate to Promote a Production Control System (Push)

Three detailed rules for implementing just in time production methods

Firstly, each process only produces the products required by the subsequent process, avoiding the production of unnecessary products

Secondly, because production is only carried out when the subsequent process requires it, it avoids and reduces the inventory of non urgently needed items

Thirdly, production instructions are only issued to the last process, and the final quantity of finished products is consistent with the quantity indicated in the production instructions (market demand)

 

The method of solving frequent order changes through lean production mechanism

Lean Production Method - Streamlined Production

Unit Process and One Piece Flow

The smaller the single production batch, the better. Ideally, the batch size is equal to each process, allowing only one product to be produced at a time. There is no need for large and high-speed machines. Quality and mechanical problems immediately arise without the need for repeated operations, reducing inventory and reducing usage space

Due to the lack of buffer inventory, the problem must be solved immediately, resulting in improved quality. This can closely link production and customer demand, shorten lead times, and increase adaptability

Selection of Unit Machines

Production process of combining different machines into units

Unit equipment must be able to produce unit products, and machines should preferably be movable

Suggestion:

Choose a machine with the same functionality but smaller volume

Choose existing machines and consider redesigning units before purchasing new ones

Adjust production pace based on production volume

Flexible deployment of employees

 

Shorten homework switching time and quickly switch - four stages

To shorten the switching time, it is necessary to do it step by step and gradually in sequence:

Stage 1: One bit minute is controlled within ten minutes

Stage 2: Reduce from a few hours or tens of minutes to half of the original

Stage 3: Complete within three minutes and move towards the goal of "zero switching"

Stage 4: "Instant Trigger", completed within one minute

Improvement rules for shortening homework switching time

The quantification and synchronization of small-scale production inevitably lead to frequent job switching. Shortening the time for job switching has become a key issue

Switching of benchmark changes for mold cutting tools, fixtures, and fixtures

Switching of component materials in assembly production

General preparation work before manufacturing

 

Lean Production - Total Equipment Maintenance (TPM)

Full staff production security can be achieved through the following six methods:

Comprehensive production security - means ensuring that the machinery and equipment are in good working condition, in a safe and stable state

1. Regular preservation 2. Anticipated preservation 3. Post preservation 4. Improved preservation 5. Preservation prevention 6. Autonomous preservation

Improper equipment maintenance concepts:

1. If it's broken, fix it again. If it's not broken, don't worry about it

2. Spending time maintaining is not very effective

3. Engage in separate battles, ensuring that the well water does not invade the river

4. The operator is only responsible for use, while the repairman is only responsible for maintenance

5. No concept of firefighting

6. It should be noted that malfunctions are always inevitable

7. All equipment is regularly overhauled and replaced on a regular basis

8. It is not necessary for all staff to participate in production and maintenance

 

Equipment mobility and availability:

Crop utilization rate=time required for daily use/maximum load time of equipment used per day

Mobility rate=available time/required time per day

The higher the mobility rate, the better. The goal is to pursue 100%, while the mobility rate depends on the situation. If you don't want to pursue 100%, it's better

If you want to move, move; if you want to stop, stop

 

Relationship between manufacturers and suppliers

Suppliers become external work centers

■ The delivery frequency becomes more frequent and is directly delivered within the workshop

Omitting incoming inspection

The quality of the supplier meets the requirements and is stable and reliable

Remote suppliers utilize nearby warehouses for batch delivery

Trend towards using a single supplier

Assist suppliers in developing just in time production systems

Ten Ways to Control Supplier Delivery Times

Plan Review Method

Production meeting coercion method

Performance management method

Man to man coercion method

Batch procurement method

Supplier Recognition Act

Liability Compensation Law

Schedule monitoring method

Warning method: 3-5 day management, shipment reminder method

Abnormal reporting method

 

Ten Measures to Improve Supplier Quality, External Quality Inspection

Tour tutoring

Audit and evaluation

Participate in the quality inspection meeting for its products

Customer Complaint Response System and Claims

Feedback method for finished product quality information

Failure cost claim method

Deduction and Penalty Laws

Quality feedback method for incoming inspection

Quality improvement

 

Supplier Control Points

Permanent Representative

Supervision and inspection

Inspection of critical or special processes

Joint inspection with customers

Control major changes

tutor

Incoming inspection

control

A Management Tool for Realizing Lean Production - Billboard Production Management

(1) Single billboard management method

The characteristic of this single billboard management method is to only use "production billboards" to issue work instructions and control the production process

The basic principles of single billboard management are as follows

② The billboard in the billboard collection box automatically sends a production instruction to process B, indicating that "if any parts are taken, they should be produced and supplemented immediately." Therefore, process B processes and produces the parts based on the "part name", "production quantity" and other information indicated on the production billboard. After processing, process B attaches the previous production billboard to the box containing the newly processed parts. Finally, Place them in the designated work in progress storage area for production billboards and replenish the parts that have been collected

② When the operator of process B is carrying out production, he also needs to use necessary parts and products. At this time, he will go to the previous process A to collect the required parts. At the same time, he will also remove the billboard attached to the parts box and put it into the billboard collection box of process A. Similarly, this billboard will automatically issue production instructions to the operator of process A, and so on, until raw material procurement or external processing orders are placed

③ When the operator of process B is carrying out production, he also needs to use necessary parts and products. At this time, he will go to the previous process A to collect the required parts. At the same time, he will also remove the billboard attached to the parts box and put it into the billboard collection box of process A. Similarly, this billboard will automatically issue production instructions to the operator of process A, and so on, until raw material procurement or external processing orders are placed

(2) The basic principles of dual billboard management

When the assembly line C receives production instructions, the operators start using the components stored in the assembly process for product assembly. At the same time, the operators remove the material retrieval billboard hanging on the component box and place it in the billboard collection box

2. After seeing the billboard inside the collection box, the movers felt as if they had received a material retrieval instruction. Therefore, they took this material retrieval billboard and an empty box to the work in progress storage area of process B to retrieve the components indicated by the billboard

3. After receiving the required components according to the information indicated on the material retrieval billboard, the mover immediately removed the production billboard originally hung on the component box and placed it in the production billboard collection box of process B. At the same time, he hung the material retrieval billboard he brought with him on the received component box and placed the empty box in the designated location. Finally, He will receive the parts and the retrieval billboard, which will be sent back to the general assembly

line

4. When the operator of process B sees the production billboard in the collection box of the production billboard, they know that "existing parts have been taken and must be produced and supplemented immediately." Therefore, the operator produces and processes the necessary number of necessary parts based on the information indicated by the production billboard

After the parts are processed, hang the production billboard on the box containing the newly processed parts and send them together to the designated storage location on the billboard, so that the handling personnel of the subsequent process can come to collect them when needed

Five usage rules for operating billboards

Without billboards, we cannot produce or transport them

Billboards can only come from post production processes

The previous process can only produce and retrieve

Some billboards must be together with the actual product and defective products cannot be handed over to subsequent processes