TOTAL QUALITY MANAGEMENT
25 Jun 2014
27 Dec 2013
Plan-Do-Check-Act (PDCA)
Something needs to change:
Something's wrong, and needs to be fixed, and you've worked hard to create a
credible vision of where you want it to be in future. But are you 100% sure
that you're right? And are you absolutely certain that your solution will work
perfectly, in every way?
Where the consequences of getting
things wrong are significant, it often makes sense to run a well-crafted pilot
project. That way if the pilot doesn't deliver the results you expected, you
get the chance to fix and improve things before you fully commit your
reputation and resources.
So how do you make sure that you
get this right, not just this time but every time? The solution is to have a
process that you follow when you need to make a change or solve a problem; A
process that will ensure you plan, test and incorporate feedback before you
commit to implementation.
A popular tool for doing just this
is the Plan-Do-Check-Act Cycle. This is often referred to as the Deming Cycle
or the Deming Wheel after its proponent, W Edwards Deming. It is also sometimes
called the Shewhart Cycle.
Deming is best known as a pioneer
of the quality management approach and for introducing statistical process
control techniques for manufacturing to the Japanese, who used them with great
success. He believed that a key source of production quality lay in having
clearly defined, repeatable processes. And so the PDCA Cycle as an approach to
change and problem solving is very much at the heart of Deming's quality-driven
philosophy.
The four phases in the
Plan-Do-Check-Act Cycle involve:
Plan: Identifying and analyzing the
problem.
Do: Developing and testing a
potential solution.
Check: Measuring how effective the
test solution was, and analyzing whether it could be improved in any way.
Act: Implementing the improved
solution fully.
These are shown in Figure 1 below.
There can be any number of
iterations of the "Do" and "Check" phases, as the solution
is refined, retested, re-refined and retested again.
How to Use the Tool
The PDCA Cycle encourages you to be
methodical in your approach to problem solving and implementing solutions.
Follow the steps below every time to ensure you get the highest quality
solution possible.
Step 1: Plan
First, identify exactly what your
problem is. You may find it useful to use tools like Drill Down,
Cause and
Effect Diagrams, and the 5 Whys
to help you really get to the root of it. Once you've done this, it may be
appropriate for you to map the
process that is at the root of the problem
Next, draw together any other
information you need that will help you start sketching out solutions.
Step 2: Do
This phase involves several
activities:
Generate possible solutions.
Select the best of these solutions,
perhaps using techniques like Impact
Analysis to scrutinize them.
Implement a pilot project on a
small scale basis, with a small group, or in a limited geographical area, or
using some other trial design appropriate to the nature of your problem,
product or initiative.
Our section on Practical
Creativity includes several tools that can help you generate ideas
and solutions. Our section on Decision
Making includes a number of tools that will help you to choose in a
scientific and dispassionate way between the various potential solutions you
generate.
Note:
The phrase "Plan Do Check Act" or PDCA is easy to remember, but it's important you are quite clear exactly what "Do" means. ""Do" means "Try" or "Test". It does not mean "Implement fully." Full implementation happens in the "Act" phase.
The phrase "Plan Do Check Act" or PDCA is easy to remember, but it's important you are quite clear exactly what "Do" means. ""Do" means "Try" or "Test". It does not mean "Implement fully." Full implementation happens in the "Act" phase.
Step 3: Check
In this phase, you measure how
effective the pilot solution has been, and gather together any learnings from
it that could make it even better.
Depending on the success of the
pilot, the number of areas for improvement you have identified, and the scope
of the whole initiative, you may decide to repeat the "Do" and
"Check" phases, incorporating your additional improvements.
Once you are finally satisfied that
the costs would outweigh the benefits of repeating the Do-Check sub-cycle any
more, you can move on to the final phase.
Step 4: Act
Now you implement your solution
fully. However, your use of the PDCA Cycle doesn't necessarily stop there. If
you are using the PDCA or Deming Wheel as part of a continuous improvement
initiative, you need to loop back to the Plan Phase (Step 1), and seek out
further areas for improvement.
When to use
the Deming Cycle
The Deming Cycle provides a useful,
controlled problem solving process. It is particularly effective for:
Helping implement Kaizen
or Continuous Improvement approaches, when the cycle is repeated again and
again as new areas for improvement are sought and solved.
Identifying new solutions and
improvement to processes that are repeated frequently. In this situation, you
will benefit from extra improvements built in to the process many times over
once it is implemented.
Exploring a range of possible new
solutions to problems, and trying them out and improving them in a controlled
way before selecting one for full implementation.
Avoiding the large scale wastage of
resources that comes with full scale implementation of a mediocre or poor
solution.
Clearly, use of a Deming Cycle
approach is slower and more measured than a straightforward "gung ho"
implementation. In true emergency situations, this means that it may not be
appropriate (however, it's easy for people to think that situations are more of
an emergency than, in reality, they really are...)
Note:
PDCA is closely related to the Spiral Development Approach which is popular in certain areas of software development, especially where the overall system develops incrementally. Spiral Development repeats loops of the PDCA cycle, as developers identify functionality needed, develop it, test it, implement it, and then go back to identify another sub-system of functionality.
PDCA is closely related to the Spiral Development Approach which is popular in certain areas of software development, especially where the overall system develops incrementally. Spiral Development repeats loops of the PDCA cycle, as developers identify functionality needed, develop it, test it, implement it, and then go back to identify another sub-system of functionality.
Key Points:
The Plan-Do-Check-Act (PDCA) Cycle
provides a simple but effective approach for problem solving and managing
change, ensuring that ideas are appropriately tested before committing to full
implementation. It can be used in all sorts of environments from new product
development through to marketing, or even politics.
It begins with a Planning phase in
which the problem is clearly identified and understood. Potential solutions are
then generated and tested on a small scale in the "Do" phase, and the
outcome of this testing is evaluated during the Check phase. "Do" and
"Check" phases can be iterated as many times as is necessary before
the full, polished solution is implemented in the "Act" phase.
The How
Here are the basic steps needed for continuous improvement:
This assumes that you have a
continuous improvement manager identified (this need not be a full time
job for small organizations—this could be as little as 30 minutes a day).
Identify a project that offers a
high certainty of visible results — you do not want to have a failure on your
first attempt — there will be plenty of time for that in the future as your
willingness to take risk grows.
Determine current performance by
base lining. Make sure your base line defines the targeted area of
improvement.
Obtain commitment of both
management and the people in the target area. Define the improvement
objective — but in terms of process change not “X” number more
widgets. This might be an improvement in quality (scrap/rework reduction),
an incremental but undefined reduction in cycle time or ergonomic improvements.
Organize the team. This will
include the program manager, the area personnel and supervisor and often
members from other areas in the plant as “fresh eyes.” Occasionally, outside
help may be beneficial.
Identify the causes of the current
performance limitations.
Define potential solutions and test
to determine if they will accomplish the improvement objective.
Document an improvement plan that
defines exactly how and by whom the changes will be implemented.
Identify and overcome (where
possible) unwarranted resistance to the change. There will always be
resistance, particularly at the beginning of this journey. Use persuasion
whenever possible but be aware that on occasion you may have to move the
resistance out of the way.
Implement the change.
Put in place controls to maintain
the changes, monitor and verify the results.
Acknowledge and reward the success. Encouragement of the people,
who have made the improvements, however small, is an important component. The
success needs to be acknowledged and publicized across the organization with
equal credit going to the entire team. Reward the team — but within
reason. A pizza party and extended lunch for the team that had a major
accomplishment might be far more appropriate in your organization than some
flashy award that can cause ill feelings across the entire organization.
Notice the PDCA diagram is a circle
— begin again!
I cannot close without a comment on
failure — it will happen. Accept that whenever you do something new or
different, failure is a possibility. DO NOT go in search of the guilty.
Understand why there was a failure, fix the cause, learn from it and move
on. If you have followed all the steps the failures will surface during
the test phase. Thus the results are only uncomfortable — and possibly
embarrassing — not catastrophic.
Obviously, I cannot do justice to
this process in the space limits of this article. There are many excellent
books available — one I will recommend is Out of the Crisis by W.
Edwards Deming, MIT 1989.
Don’t follow the path — make one —
begin the trip and enjoy the journey!
One more Plan-Do-Check-Act (PDCA)
Cycle
Also called: PDCA,
plan–do–study–act (PDSA) cycle, Deming cycle, Shewhart cycle
The plan–do–check–act cycle (Figure
1) is a four–step model for carrying out change. Just as a circle has no end,
the PDCA cycle should be repeated again and again for continuous improvement.
Figure 1: Plan-do-check-act cycle
When to Use Plan–Do–Check–Act
As a model for continuous
improvement.
When starting a new improvement
project.
When developing a new or improved
design of a process, product or service.
When defining a repetitive work
process.
When planning data collection and
analysis in order to verify and prioritize problems or root causes.
When implementing any change.
Plan–Do–Check–Act Procedure
Plan. Recognize an opportunity and
plan a change.
Do. Test the change. Carry out a
small-scale study.
Check. Review the test, analyze the
results and identify what you’ve learned.
Act. Take action based on what you
learned in the study step: If the change did not work, go through the cycle
again with a different plan. If you were successful, incorporate what you
learned from the test into wider changes. Use what you learned to plan new
improvements, beginning the cycle again.
Plan–Do–Check–Act
Example (use for case study)
The Pearl
River , NY School District, a 2001 recipient of the Malcolm
Baldrige National Quality Award, uses the PDCA cycle as a model for defining
most of their work processes, from the boardroom to the classroom.
PDCA is the basic structure for the
district’s overall strategic planning, needs–analysis, curriculum design and
delivery, staff goal-setting and evaluation, provision of student services and
support services, and classroom instruction.
Figure 2 shows their “A+ Approach
to Classroom Success.” This is a continuous cycle of designing curriculum and
delivering classroom instruction. Improvement is not a separate activity: It is
built into the work process.
Plan. The A+ Approach begins with a
“plan” step called “analyze.” In this step, students’ needs are analyzed by
examining a range of data available in Pearl River ’s
electronic data “warehouse,” from grades to performance on standardized tests.
Data can be analyzed for individual students or stratified by grade, gender or
any other subgroup. Because PDCA does not specify how to analyze data, a
separate data analysis process (Figure 3) is used here as well as in other
processes throughout the organization.
Figure 3:
Do. The A+ Approach continues with
two “do” steps:
“Align” asks what national and
state standards require and how they will be assessed. Teaching staff also
plans curriculum by looking at what is taught at earlier and later grade levels
and in other disciplines to assure a clear continuity of instruction throughout
the student’s schooling. Teachers develop individual goals to improve their
instruction where the “analyze” step showed any gaps.
The second “do” step is, in this
example, called “act.” This is where instruction is actually provided,
following the curriculum and teaching goals. Within set parameters, teachers
vary the delivery of instruction based on each student’s learning rates and
styles and varying teaching methods.
Check. The “check” step is called
“assess” in this example. Formal and informal assessments take place
continually, from daily teacher “dipstick” assessments to every-six-weeks
progress reports to annual standardized tests. Teachers also can access comparative
data on the electronic database to identify trends. High-need students are
monitored by a special child study team.
Throughout the school year, if
assessments show students are not learning as expected, mid-course corrections
are made such as re-instruction, changing teaching methods and more direct
teacher mentoring. Assessment data become input for the next step in the cycle.
Act. In this example the “act” step
is called “standardize.” When goals are met, the curriculum design and teaching
methods are considered standardized. Teachers share best practices in formal
and informal settings. Results from this cycle become input for the “analyze”
phase of the next A+ cycle.
Is − Is not
When to use it
Use it when you are defining a
problem to decide what is in scope and what is not going to be considered at
this time.
Use it also when you are part of
the way through a problem and you are not sure what you are trying to do and
what is not so important.
You can also use it when planning a
solution, to help decide what to include and what to exclude.
Build the basic diagram
Draw the basic table as below. If
you are working with a group, do it on a flipchart page or a whiteboard.
Add a description of the overall
situation at the top of the page. Use a separate sheet if you need more than a
few words.
Add 'is' and 'is not' elements
Now simply as 'What is included
here?' and 'What is not included here?', writing these down in either column as
appropriate. Where it is a close division, you can add examples to clarify what
falls either side of the line.
The bottom line for deciding where
to place any point is to ask yourself questions such as:
Who cares about this?
What will happen if we do nothing
about it?
Do we have the authority to work on
this?
What do I know about this already?
Do we care about this?
Will we actually do something about
this?
Do be careful when asking these
questions, as you may 'throw the baby out with the bathwater' if you make
incorrect assumptions about such as what authority you have and what you can
actually solve.
Example
Situation: Wheels on car keep going out of balance
|
|
Is
|
Is not
|
Wheel problem
After high speed drivingOn one car only My problem Urgent On ABC tyres only Expensive
Front
wheels only
|
Suspension problem
When driving around townOn other cars of same make Jane's problem To be put off (like other problems) |
Is-Is not analysis works by making
you deliberately think about the problem and in particular the boundaries of
what it is or is not. It thus helps to create focus in attention and
consequently is more likely to lead to the right problem being solved - it is a
very common issue that an unclear boundary can lead to wandering off the path
and solving unimportant problems.
1. System Contradictions :
We begin with " 5W's and an H
" of Innovation. Ask these question of every system so that the system
function and problem is identified.
W1.
Who has the problem?
W2.
What does the problem seem to be? What are the resources?
W3.
When does the problem occur? Under what circumstances?
W4.
Where does the problem occur?
W5.
Why does the problem occur? What is root cause?
And
H1.
How does the problem occur? How can the problem be solved?
1Q.
Who has the problem? : This clearly identifies the person connected with
the problem. He could be one who is using the final product or anyone in the
line-up of concept-to-market or a person at any of the product Life-stages
(listed below),
stage
1: manufacture
stage
2: packaging
stage
3: storage
stage
4: transportation
stage
5: installation
stage
6: operation / use
stage
7: maintenance
stage
7: repair
2Q. What does the problem seem to be? What are the resources? :
Problem specification,
1. Try to specify a
conflict/contradiction
-- as a technical contradiction
or as a physical contradiction
2. Try to specify a harmful
action/interaction/effect
3. Try to specify an inefficient
useful action/interaction/effect
Determine what is a possible remedy by using a TRIZ tool (keeping track
of the resources):
1a. Technical Contradiction
: use Contradiction Matrix (39 parameters and 40 inventive principles)
1b. Physical Contradiction : use
separation principles (space, time, structure - parts/whole, on condition)
2. Harmful action/effect : use direct or
indirect elimination and standard
solutions
3. Inefficient useful
action/effect : use standard solutions and scientific effects
3Q. When does the problem occur?
Under what circumstances? Determine whether
-- Time of conflict is
before Time of operation
-- Time of conflict is
during Time of operation
-- Time of conflict is
after Time of operation
Determine what are the available
time resources
Possible remedy using a TRIZ tool
:
-- Use “separation-in-time” principle for
eliminating physical contradiction
4Q.
Where does the problem occur? Determine what is the zone of conflict
>> where is the zone of conflict in relation to the Zone of
operation?
-- zone of conflict is
in the Super-system
-- zone of conflict is
same as zone of operation
-- zone of conflict is
in the Sub-system
Determine what are the available
space resources
Possible remedy using a TRIZ tool
:
-- Use “separation-in-space” principle for
eliminating physical contradiction
5Q. Why does the problem occur?
{“Ask WHY5 times “ - W. E. Deming } :
Identify the ‘function’ that
creates/leads to the problem :
Identify 2 substances ( “tool” and “object” ) and 1 field
(energy, enabling, acting force)
Is “tool”, “object” or “field”
causing the problem?
Determine what are the available
substance/field resources
Possible remedy by using a TRIZ
tool:
1. Harmful action/effect : use direct
or indirect elimination and standard solutions
2. Inefficient useful
action/effect : use standard solutions
and scientific effects
1H.
How does the problem occur?
Keep asking “ How? ”
till you reach the ‘root cause’ of the problem
" 5W's and an H ” leads to a clear understanding of the problem
along with
the ideal final result, the resources available and the
possible TRIZ tools to solve the problem.
Poka Yoke
Poka Yoke is a quality management concept developed by a Matsushita manufacturing engineer named Shigeo Shingo to prevent human errors from occurring in the production line. Poka yoke (pronounced “poh-kah yoh-kay”) comes from two Japanese words – “yokeru” which means “to avoid”, and “poka” which means “inadvertent errors.” Thus, poka yoke more or less translates to “avoiding inadvertent errors”.
Poka yoke is sometimes referred to in English by some people as “fool-proofing”. However, this doesn’t sound politically correct if applied to employees, so the English equivalent used by Shingo was “error avoidance.” Other variants like “mistake proofing” or “fail-safe operation” have likewise become popular.
The main objective of poke yoke is to achieve zero defects. In fact, it is just one of the many components of Shingo’s Zero Quality Control (ZQC) system, the goal of which is to eliminate defective products.
Poka yoke is more of a concept than a procedure. Thus, its implementation is governed by what people think they can do to prevent errors in their workplace, and not by a set of step-by-step instructions on how they should do their job.
Poka yoke is implemented by using simple objects like fixtures, jigs, gadgets, warning devices, paper systems, and the like to prevent people from committing mistakes, even if they try to! These objects, known as poka yoke devices, are usually used to stop the machine and alert the operator if something is about to go wrong.
Anybody can and should practice poka yoke in the workplace. Poke yoke does not entail any rocket science – sometimes it just needs common sense and the appropriate poka yoke device. Poka yoke devices should have the following characteristics: 1) useable by all workers; 2) simple to install; 3) does not require continuous attention from the operator (ideally, it should work even if the operator is not aware of it); 4) low-cost; 5) provides instantaneous feedback, prevention, or correction. A lot of Shingo’s poka yoke devices cost less than $50!
Of course, error-proofing can be achieved by extensive automation and computerization. However, this approach is expensive and complicated, and may not be practical for small operations. Besides, it defeats the original purpose of poka yoke, which is to reduce defects from mistakes through the simplest and lowest-cost manner possible.
Poka yoke is at its best when it prevents mistakes, not when it merely catches them. Since human errors usually stem from people who get distracted, tired, confused, or demotivated, a good poka yoke solution is one that requires no attention from the operator. Such a poka yoke device will prevent the occurrence of mistake even if the operator loses focus in what she is doing.
Examples of ‘attention-free’ Poke Yoke solutions:
1) a jig that prevents a part from being misoriented during loading
2) non-symmetrical screw hole locations that would prevent a plate from being screwed down incorrectly
3) electrical plugs that can only be inserted into the correct outlets
4) notches on boards that only allow correct insertion into edge connectors
5) a flip-type cover over a button that will prevent the button from being accidentally pressed
Three levels of Poka-Yoke:
1) elimination of spills, leaks, losses at the source or prevention of a mistake from being committed
2) detection of a loss or mistake as it occurs, allowing correction before it becomes a problem
3) detection of a loss or mistake after it has occurred, just in time before it blows up into a major issue (least effective)
Kanban Production Control System
A kanban or “pull” production
control system uses simple, visual signals to control the movement of materials
between work centers as well as the production of new materials to replenish
those sent downstream to the next work center. Originally, the name kanban
(translated as “signboard” or “visible record”) referred to a Japanese shop
sign that communicated the type of product sold at the shop through the visual
image on the sign (for example, using circles of various colors to indicate a
shop that sells paint). As implemented in the Toyota Production System, a
kanban is a card that is attached to a storage and transport container.
It identifies the part number and container capacity, along with other
information, and is used to provide an easily understood, visual signal that a
specific activity is required.
In Toyota ’s dual-card kanban system, there are
two main types of kanban:
1. Production Kanban: signals the
need to produce more parts
2. Withdrawal Kanban (also called a
“move” or a “conveyance” kanban): signals the need to withdraw parts from one
work center and deliver them to the next work center.
In some pull systems, other
signaling approaches are used in place of kanban cards. For example, an
empty container alone (with appropriate identification on the container) could
serve as a signal for replenishment. Similarly, a labeled, pallet-sized
square painted on the shop floor, if uncovered and visible, could indicate the
need to go get another pallet of materials from its point of production and move
it on top of the empty square at its point of use.
A kanban system is referred to as a
pull‑system, because the kanban is used to pull parts to the next production
stage only when they are needed. In contrast, an MRP system (or any
schedule‑based system) is a push system, in which a detailed production
schedule for each part is used to push parts to the next production stage when
scheduled. Thus, in a pull system, material movement occurs only when the
work station needing more material asks for it to be sent, while in a push
system the station producing the material initiates its movement to the
receiving station, assuming that it is needed because it was scheduled for
production. The weakness of a push system (MRP) is that customer demand
must be forecast and production lead times must be estimated. Bad guesses
(forecasts or estimates) result in excess inventory and the longer the lead
time, the more room for error. The weakness of a pull system (kanban) is
that following the JIT production philosophy is essential, especially
concerning the elements of short setup times and small lot sizes, because each
station in the process must be able to respond quickly to requests for more
materials.
Dual-card
Kanban Rules:
No parts are made unless there is a
production kanban to authorize production. If no production kanban are in
the “in box” at a work center, the process remains idle, and workers perform
other assigned activities. This rule enforces the “pull” nature of the
process control.
There is
exactly one kanban per container.
Containers for each specific part
are standardized, and they are always filled with the same (ideally, small)
quantity. (Think of an egg carton, always filled with exactly one dozen
eggs.)
Decisions regarding the number of
kanban (and containers) at each stage of the process are carefully considered,
because this number sets an upper bound on the work-in-process inventory at
that stage. For example, if 10 containers holding 12 units each are used to
move materials between two work centers, the maximum inventory possible is 120
units, occurring only when all 10 containers are full. At this point, all
kanban will be attached to full containers, so no additional units will be
produced (because there are no unattached production kanban to authorize
production). This feature of a dual-card kanban system enables systematic
productivity improvement to take place. By deliberately removing one or
more kanban (and containers) from the system, a manager will also reduce the maximum
level of work-in-process (buffer) inventory. This reduction can be done
until a shortage of materials occurs. This shortage is an indication of
problems (accidents, machine breakdowns, production delays, defective products)
that were previously hidden by excessive inventory. Once the problem is
observed and a solution is identified, corrective action is taken so that the
system can function at the lower level of buffer inventory. This simple,
systematic method of inventory reduction is a key benefit of a dual card kanban
system.
Just in time production (JIT)
Just in time is a ‘pull’ system of production, so actual orders provide a signal for when a product should be manufactured. Demand-pull enables a firm to produce only what is required, in the correct quantity and at the correct time.
This means that stock levels of raw materials, components, work in progress and finished goods can be kept to a minimum. This requires a carefully planned scheduling and flow of resources through the production process. Modern manufacturing firms use sophisticated production scheduling software to plan production for each period of time, which includes ordering the correct stock. Information is exchanged with suppliers and customers through EDI (Electronic Data Interchange) to help ensure that every detail is correct.
Supplies are delivered right to the production line only when they are needed. For example, a car manufacturing plant might receive exactly the right number and type of tyres for one day’s production, and the supplier would be expected to deliver them to the correct loading bay on the production line within a very narrow time slot.
Advantages of JIT
1. Lower stock holding means a reduction in storage space which saves rent and insurance costs
2. As stock is only obtained when it is needed, less working capital is tied up in stock
3. There is less likelihood of stock perishing, becoming obsolete or out of date
4. Avoids the build-up of unsold finished product that can occur with sudden changes in demand
5. Less time is spent on checking and re-working the product of others as the emphasis is on getting the work right first time
Disadvantages of JIT
1. There is little room for mistakes as minimal stock is kept for re-working faulty product
2. Production is very reliant on suppliers and if stock is not delivered on time, the whole production schedule can be delayed
3. There is no spare finished product available to meet unexpected orders, because all product is made to meet actual orders – however, JIT is a very responsive method of production
Some Key Elements of JIT
1. Stabilize and level the MPS with uniform plant loading (heijunka in Japanese): create a uniform load on all work centers through constant daily production (establish freeze windows to prevent changes in the production plan for some period of time) and mixed model assembly (produce roughly the same mix of products each day, using a repeating sequence if several products are produced on the same line). Meet demand fluctuations through end item inventory rather than through fluctuations in production level. Use of a stable production schedule also permits the use of backflushing to manage inventory: an end item’s bill of materials is periodically exploded to calculate the usage quantities of the various components that were used to make the item, eliminating the need to collect detailed usage information on the shop floor.
2. Reduce or eliminate setup times: aim for single digit setup times (less than 10 minutes) or “one touch” setup – this can be done through better planning, process redesign, and product redesign. A good example of the potential for improved setup times can be found in auto racing, where a NASCAR pit crew can change all four tires and put gas in the tank in under 20 seconds. (How long would it take you to change just one tire on your car?) The pit crew’s efficiency is the result of a team effort using specialized equipment and a coordinated, well-rehearsed process.
3. Reduce lot sizes (manufacturing and purchase): reducing setup times allows economical production of smaller lots; close cooperation with suppliers is necessary to achieve reductions in order lot sizes for purchased items, since this will require more frequent deliveries.
4. Reduce lead times (production and delivery): production lead times can be reduced by moving work stations closer together, applying group technology and cellular manufacturing concepts, reducing queue length (reducing the number of jobs waiting to be processed at a given machine), and improving the coordination and cooperation between successive processes; delivery lead times can be reduced through close cooperation with suppliers, possibly by inducing suppliers to locate closer to the factory.
5. Preventive maintenance: use machine and worker idle time to maintain equipment and prevent breakdowns.
6. Flexible work force: workers should be trained to operate several machines, to perform maintenance tasks, and to perform quality inspections. In general, JIT requires teams of competent, empowered employees who have more responsibility for their own work. The Toyota Production System concept of “respect for people” contributes to a good relationship between workers and management.
7. Require supplier quality assurance and implement a zero defects quality program: errors leading to defective items must be eliminated, since there are no buffers of excess parts. A quality at the source (jidoka) program must be implemented to give workers the personal responsibility for the quality of the work they do, and the authority to stop production when something goes wrong. Techniques such as “JIT lights” (to indicate line slowdowns or stoppages) and “tally boards” (to record and analyze causes of production stoppages and slowdowns to facilitate correcting them later) may be used.
8. Small lot (single unit) conveyance: use a control system such as a kanban (card) system (or other signaling system) to convey parts between work stations in small quantities (ideally, one unit at a time). In its largest sense, JIT is not the same thing as a kanban system, and a kanban system is not required to implement JIT (some companies have instituted a JIT program along with a MRP system), although JIT is required to implement a kanban system and the two concepts are frequently equated with one another.
Kaizen
Kaizen is a Japanese word meaning “Change for the good” or as we have come to know it
today as meaning “Continuous Improvement.” The meaning was initially used as a Japanese philosophy of
continuously improving everything we come in contact with during our lifetime.
When we refer Kaizen to our place
of work it means to improve all facets, functions and processes within that
business, from enquiry, concept, product or service processing, administration,
office work, engineering, maintenance, IT, stores, logistics, planning,
everything we do within that business and their suppliers should be subjected
to Kaizen. By continuously improving tilization systems, processes and
support activities we improve Quality, Delivery Time, Service and Cost.
Kaizen is generally thought to be
one of the essential and key parts of Lean and aims to eliminate Waste in the
form of Non Value Adding work and when applied through employee teamwork, tilizati
the work place.
Three Forms
of Waste
1. Mura
Unevenness in work demand or work
flow. When embarking on JIT the first thing to do is to establish tiliza work
flow (Heijunka) then create a system or combination of systems that triggers
and signals pull work flow.
2. Muri
Having a greater demand than
capacity in any given time or overburdening the process, series of processes or
system. We can all generally relate to making mistakes when we are rushed or
stressed this is caused by Muri. So we establish the capacity for work, (Noting
that JIT needs for us to only plan to use 85% of capacity for some flexibility)
and then ensure we do not try and force more into the system than it can
handle.
8.
Muda
There are type 1 and 2 Muda.
Type 1 is the necessary but non value adding waste. This is where from a business perspective we do it to meet regulations, cannot afford to duplicate, such as Pharmacies on every floor of a hospital, photocopiers, faxes and printers on every desk etc.
Type 2 is unnecessary, non value adding waste.
Type 1 is the necessary but non value adding waste. This is where from a business perspective we do it to meet regulations, cannot afford to duplicate, such as Pharmacies on every floor of a hospital, photocopiers, faxes and printers on every desk etc.
Type 2 is unnecessary, non value adding waste.
Muda is where
the 7+1 lean waste resides.
1. Transport – Moving
materials, people, files, documents, items of any type, products, information,
by any means including electronically.
2. Inventory
– Storage of any type of any item, information, document.
3. Motion – Bending,
reaching, turning, lifting, and equipment left idling, any motion not creating
value, like drilling air before contacting the work piece.
4. Waiting –
in queues, for parts, for information, for instructions, for schedules, for
equipment, for software, for previous process and for testing etc.
5. Over producing or production – basically making or producing more than the downstream customer
immediately requires. Referred to as the biggest waste of lean.
6. Over Processing – Activity that does not add value or features for the end user, such
as using materials of higher grade than required, producing to tighter
tolerances than necessary, longer vintage time in wine making, over filling
etc.
7. Defects or defective work – Includes any rework, scrap, incorrect information, inspection
requirements, over compensating for excessive variation.
8. Skills and tilization – Not affectively using the collective talents, skills and
knowledge of all employees and suppliers.
26 Dec 2013
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