Chapter 5 Create Connected Process Flow
One-Piece Flow (Continuous Flow)
 Primary Purpose of Lean: Identification & Elimination of Waste. The method for achieving that
objective-- move toward continuous flow
 Products that move continuously through the processing steps with minimal waiting time in
between, and the shortest distance traveled.
 Serves to surface any problem that would inhibit flow. Forces the correction of problems, thus
reducing waste
 Connecting two or more processes in continuous flow will increase the severity of problems
thereby intensifying the need to resolve the problem. (Connecting major processes an issue
could halt the entire facility)
 Toyota sees situations, such as a problem that stops production entirely, as an opportunity to
identify and attack the weakness within to strengthen the overall system.
 “Failing” and correcting the shortcoming is a way to improve results long term.
 Prepare for flow
o Must look to eliminating major issues
o Start planning and developing a discipline for problem solving
o Have comprehensive understanding of lean tools
 First step back and understand the purpose of continuous flow: drive away waste from the
operation
 Maintaining continuous flow between processes will create a linkage, making each process
dependent on each other. Making any disruption to these processes more critical.
Less Is More: REDUCE WASTE (over arching theme of the chapter)
 Toyota considers overproduction to be the worst of all the types of waste. What are examples
of overproduction in each of our areas?
 Toyota stresses the concept to STOP and stand and do nothing as opposed to continuing
overproduction. This allows everyone to see and understand the amount of opportunity
available.
 Items to reflect on regarding Naval Air Depot Case Study:
o Assumption/belief that planes came in for repair unpredictably Each of our
departments all are ‘putting out fires’ when questions arise or reports are needed or
something breaks.
o Incorporated the 5S to significantly reduce time
o Management needed to be educated in the process and stop brining in additional
aircrafts whenever one arrived.
Single-Piece Flow
 Achieving single-piece flow is extremely difficult and requires a highly refined process and very
specific conditions
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Some strategies in creating Connected Process Flow:
o Continued elimination of waste
o Force problems to surface
o Make problems uncomfortable
o Establish connected processes to create interdependency
o Identify weak links in the flow and strengthen them
Example of bucket brigade: Timing between members is critical to avoid wasted time
Provide a certain degree of urgency for problems, so they’re not ignored, and also a degree of
cushion until the capability of the operation is improved and a tighter level can be sustained
Well established continuous connected flow provides signals, which gives everyone early
warning indicator
Key Criteria for Achieving Flow
 Ensure consistent capability, primary intent of stability phase
 Consistent capability requires consistent application and availability of resources
 Reliability of processes and equipment is imperative
 Operation cycle times must be balanced to the takt time
Pull
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Flow: defines the state of material as it moves from process to process
Pull: dictates when material is moved and who determines that it is to be moved
Three primary elements of pull
o Defined agreement, between supplier & customer, which specified limits pertaining to
volume of product
o Dedicated items that are shared between two parties must be dedicated to them.
o Control methods that must be visually apparent and physically constrained
Establishing the three elements necessary for pull then creates the defined connections
between operations
In a PUSH system this is no defined agreement, the supplier works at his/her own pace and
provides to the customer according to his own schedule.
A PULL system is an aggregation of several elements that support the process of pulling; a
signally method for the customer to say “I am ready for more”
Strong emphasis on VISUAL AGREEMENTS. How or What can we create with/for our customers?
When deviation occurs this is a clear message there is an underlying problem. Mgmt typically
blame the operator and not contemplate why they are deviating. Primary causes of deviation:
o Imbalanced work cycle times (person with extra time on their hands)
o Intermittent work stoppages due to lack of parts or correcting defects in work
o Intermittent work delays due to struggles with machines or overly difficult tasks
o Miscellaneous issues
High-variety, high-mix, custom environment –much like each of our own areas. For this type of
flow to work well, each operator must have the capability (or knowledge resource) to produce
any model that comes at any time
Pull Between Separate Operations (Departments)
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Always Satisfy the Customer
Must establish an agreement that is visible; define the max and min allowable
A mechanism must be used to provide visual awareness for customer needs and status
Consider breaking down products/processes into different value streams based on complexity
SUMMATION: Identify Waste then Eliminate Waste then Identify Waste then Eliminate Waste