Lean Production II

show detailed necessary activities and provide a uniform training method for employee qualifications

• benefits:
• - training document
• - captures key qualifications which are necessary to process standard operating steps
• - identifies special tools, quality, safety aspects
• - leads to collective understanding of processes

• 1) record sequence of job
• 2) determine material, tools, equipment/machines to do the job
• 3) diagram work movement
• 4) identify waste
• 5) determine improving actions to achieve desired results (eg takt time)
• 6) create flow, define standard inventory
• 7) document method

• first row: manual work
• second row: automatic work
• third row: transportation/walking

• together with Standard Work Chart:
• - shows combination of automatic and manual work
• - allows analysis of man machine relationship

it is not acceptable to make operator wait for machine

• Workers must be:
• - capable of keeping defined standards
• - willing to keep them

• Leaders must:
• - support people to deliver right results
• - train and qualify people
• - be present on shop floor/Gemba
• - implement simple controls (visualisation, KPIs, ANDON, Takt time...)
• - check controls, understand abnormalities and react
• - support problem solving process, improve and standardize again

• diagram: x: right behaviour, y: maturity
• down left: no standard defined
• -standard defined but not known&trained
• -standard defined, visualized&known but no called for
• - standard defined, known, called for, followed
• up right: standard continuously challenged&improved = KAIZEN, standard work

• - does a standard exist?
• - is the standard up to date?
• - do employees know the standard?
• - is work performed according to the standard?

--> only if all questions are answered with yes, it very likely is standard work

For KAIZEN there must be system to highlight abnormalities and learn form them

• variability (product families, exotics are isolated)
• work task repeatability (work not defined/only few if..then rules)
• equipment reliability (line and equipment must be reliable, downtime should be minimal)
• technical process stability (quality issues must be minimal, right process parameters deliver stable result)
• material availability (no interruption, searching)

• long term creation of corporate culture, in which order and cleanliness are matter of courses
• stability of all processes, esp. in areas with many employees and little space av.
• safety and health at work
• toll to prepare flow

• Sort:
• get rid of everything that avoids better process, create space for better arrangement
• Shine:
• cleaning is inspecting!cleaning/inspection plans
• Straighten:
• reduce waste, improve ergonomics, create flow
• Standardize:
• clear and simple instructions
• Sustain:
• Observation, Challenge and continuous improvement of standards (review by audits and checklists)

• Seiri
• Seiso
• Seiton
• Seiketsu
• Shitsuke

• immediate identification of deviations without further tools
• realize just by walking through an area whether standards are kept and the process is in order

• standard -> make standard visible -> able to verify adherence to standard -> discover deviation -> report deviation -> correct deviation -> standard
• => clear and understandable

• every kind of signals, displays or sounds, which deliver...
• .. what we need to know
• ... when we need to know it
• ... where we need to know it
• in a form that is CLEARLY UNDERSTOOD

improvement process addressing abnormalities highlighted by visual controls

Abnormality -> visualisation ->process improvement

• only visualize, if
• 1) there is a standard
• 2) the standard is controlled
• 3) deviation leads to defined reaction

• identity and location (keep basic order&flow)
• work documents(ensure standard work practices)
• process state (detect normal from abnormal)
• performance(adequately react to performance gaps on all levels)
• improvement processes (support teams&install a self propelled process)

• support target deployment process, give teams opportunity to monitor and improve their own processes
• - team charts with current vs. target performance, supplemented by other KPI's (quality, cost time)
• - control charts for process stability (in target area with minimal deviation)
• - safety information (nr. of accidents and their causes)

• Problem solving workflow
• Action Plan (PDCA)
• Pareto diagram
• cause and effect diagram (fishbone)

• muda - waste
• mura - unevenness
• muri - overburden

• takt
• inventory
• sequence

• total available time (min/day)
• /
• total customer demand (products/day)
• = customer takt (min/product)

• finished goods inventory held (expensive)
• low WIP inventory
• smoothened capacity utilisation
• high degree of stability
• foundation to process improvement

a revolving production schedule distributes work evenly among the process steps of the production sequence at all times

• 1) stabilisation
• 2) leveling by volume
• 3) leveling by type
• 4) sequencing

• stable processes and plant availability,
• stable suppliers,
• clear understanding of capacity available

• leveling by volume:
• clear understanding of customer demand, stable
• production volume over planning period, understanding customer takt

• leveling by type:
• understanding changeover,
• adjusting customer takt,
• definition of runners&exotics,
• definition of pitch size,
• building a daily leveled schedule,
• operating at heijunka box

• sequencing :
• stabilise planning process,
• improve availability of material and
• equipment,
• reduce and stabilise changeover,
• reduce pitch size,
• reduce EPEI

if changeover times are irrelevant --> basis for planning is customer takt

if changeover times are >>0 --> production must index faster than customer takt to fulfill customer demand

• planned production time - changeover timeloss /
• customer demand = adjusted customer takt

• runners: will be produced every day following a constant volume and cyclic schedule
• exotics: will be produced once a week at free time slots

number of runners depends on largest number of possible changeovers per week

= changeover time provision (min/week) / changeover time (min/changeover)

• n_{planning days} x n_runners + n_exotics
• with n_runners + n_exotics = n_types
• rule: choose split between runners and exotics so that
• 1. planned <= largest no. of changeovers
• 2. planned changeovers --> max

• example:
• 3 runners/day x 5 days + 8 ex = 23
• 4 runners/day x 5 days + 7 ex = 27
• 5 runners/day x 5 days + 6 ex = 31

largest no of changeovers = 28 --> choose 27 combination

• standardised planning increment
• pitch = n x box size x customer takt
• - is multiple of customer takt
• - is the time increment of work released at the pacemaker process
• - equals or is a multiple of standardised material quantity moved between processes
• the higher leveling maturity, the smaller the pitch

• heijunka box is a tool to level mix and volume of production using kanban within a facility at fixed intervals (also called: leveling box)
• - each horizontal row is for one type of product
• - each vertical column represents identical time intervals for paced withdrawal of kanban
• - slots represent material and information flow timing
• - kanban in the slots each represents one pitch of production for one product type

• because...
• it synchronizes the whole production process with the customer takt
• it controls processes which are located upstream via pull
• it receives production plan as the only process

• 1) customer sends orders to company
• 2) orders are translated in kanban-cards and sorted into heijunka board
• 3) material supplier picks up removal-kanban of every pitch and takes it to pacemaker
• 4) upstream processes are initiated via removal-kanban

• idealistic: tool to level production by volume and type with ideal of producing every part every day
• stability: leveling for internal benefit of standardised and stabilised value stream with aligned resources (equipment, materials, people, methods)
• improvement: improvement approach to push process to higher degrees of flexibility and responsiveness to changing customer demand

• Every Part Every Interval = No. of types/largest no. of changeovers
• shortest possible time interval to produce a product program whilst achieving required quantity

• understanding customer demand
• understanding customer takt
• understanding changeover
• largest number of changeovers
• definition of runners and exotics
• definition of pitch size
• definition of leveled weekly schedue
• definition of pitch cycles for replenishment
• implementation of daily heijunka schedule
• stabilisation and reduction of EPEI

• Definition:
• to produce and transport within the entire value stream
• - what is needed
• - when it is needed
• - where it is needed
• - in the quantity and quality, which is needed
• also know as 5R (right product, quality, time, quantity and place)

goal: reduce production costs, increase flexibility

approach: provides steady, stable processes in order to achieve continuous flow production with minimal stocks

• takttime planning
• continuous flow
• pull system
• quick changeover
• integrated logistics

• - product is delivered form finished goods supermarket
• - production process is synchronized with customer demand and procedures only with presence of production order
• - system efficiency has priority - not machine load factor

• flowing reduces throughput time and shortens cost to cash cycle
• surfaces any problem immediately that would inhibit that flow
• creation of flow forces correction of problems and creates need for quality improvements

• high changeover times
• shared assets are used by different value streams
• process times are much higher than customer takt
• great distance between processes
• processes are unsteady

• disconnected stability (of single operation)
• multiprocess connected stability (multiple operations)
• value stream connected stability

• Waste Elimination (Philosophy)
• Create Continuous Flow(Principle) -> Reduced Lead Times (Performance Measures)
• Create independent connected processes (Strategy)
• Pull System(Method)->Kanban, Supermarkets, Defined FiFo Lanes(Tools)
• Problems are surfaced quickly&critical(reason)
• problems must be corrected quickly (effect)-->management reviews reports,adjusts standards(control method)
• Waste is reduced!(result)

• creates revolving stock of constant amount
• reduces transport,movements,space by moving processes closer together
• reduction of scrap
• illustrates waste within process(waiting time,stock)and supports continuous improvement

• minimal lead times
• small stocks without intermediate buffer
• minimal land requirements
• high quality
• low investment
• requirement: high availability of plants

• 1) defined agreement between supplier and customer
• 2) shared items between parties clearly dedicated
• 3) simple controls in place to support adherence of above

• low coordination effort
• stocks in line with demand
• short lead times
• but:higher suscetibility to failure due to less stocks

• def: in pull-system production processes are controlled by their direct customer,ie what and when to produce is defined by the customer
• goal: produce exactly the quantity demanded by customer, not more!
• approach: integrate information flow and material flow between each stage of production and its direct customer

• FIFO: system in which components are handled in same order(up and downstream)
• Supermarket: characterized by defined stock between processes that include all types
• Mix-Pull:uses a FIFO system or supermarket depending on variant

• demand:
• high    Supermarket           Mix-Pull
• low     FIFO/Supermarket   FIFO
•            low                        high
• Number of variants

• predefined spot for each variant
• labeling of storage location
• defined max and min stock
• visual control of upstream process according to principle "if one thing leaves, sth new has to come in"
• removal of parts according to principle "fist in-first out"

• traditional: batch&queue
• Push/Scheduled (schedule each process and push to next)
• supermarket pull (kanban)(upstream process replenishes what downstream customer took away)
• sequenced pull(broadcast)(Pull from a feeder in sequence)
• FIFO sequenced flow (defined lane with defined standard WIP between unlinked processes in FIFO sequence)
• Continuous flow(1pc flow)(physically link process steps with no inventory between)
• Ideal state of Lean

no of kanbans = response time/consumption time per container

• Single Minute Exchange of Dies
• Def: scientific approach to set up time reduction that can be applied in any factory at any machine
• procedure:
• separates between internal and external procedures
• converts internal into external set up
• streamlines all aspects of set up operation

time between the last part of the old product manufactured at normal speed until first part of new product manufactured at normal speed

• analysis of changeover process
• evaluation:internal, external or waste
• convert internal to external steps
• reduce internal steps
• optimize external steps
• standardize process

• internal: during standstill
• external: before/after standstill

• with short changeover times small batch production is cost effective.
• Rule of Thumb: doubled changeover frequency -> 50% less inventories

• materials, tools, fixtures, gauges need to be made available before machine stops!
• cleaning, removal of tools,equipment, filling out of forms etc is to be organized after the start of next type

• parallelization of steps
• additional capacity

reduce effort needed for adjustments(self aligning fixtures)

adjusted fixtures quick clamps

• pear-shaped holes
• u-shaped washers
• split thread
• u-slot

• reduction of all walking and transportation distances
• - position all tools, materials, equipment in shortest possible distance from machine
• - modify machine: switches, buttons, handles should be in one central position
• define shortest possible route for operator
• double equipment that is needed in different workplaces to eliminate loss of time caused by transportation and waiting