Efficient Material Transport in Lean Production The Drive & Control Company
Efficient Material Transportin Lean Production
The Drive & Control Company
Avoiding waste with lean production
The global trend towards “lean production” continues to gain strength.This manufacturing concept provides an optimum framework for efficient,competitive production and is based on a philosophy of consistentwaste avoidance.
2
Lean production and automation:a contradiction in terms?
Today, lean production is usually associatedwith manual production systems. Suchsystems are currently in trend and are suc-cessfully integrated into numerous assemblyprocesses and in various sectors of industry.Lean production does not, however, elimi-nate automated transport. Transferringparts manually can cause a drop in quality,for example, or a loss of valuable timeresulting in an increase in per piece costs.Finding the most economically efficienttransport solution depends on the followingproduction factors:• Batch size and variety of models• Production cycle time • Part weight and size• Takt time
How to become “lean”:• Reduce inventory• Eliminate downtime• Reduce space requirements• Avoid errors• Avoid inefficient processes• Avoid overproduction• Shorten transport routes
When does automation make sense?
Automated production or, in other words, the automated transfer of parts, is always the rightchoice if one can cut costs and increase process reliability in comparison to a manual solution.The savings gained through automation must offset the higher investment costs. Of course, inmany situations, the best solution is a combination of manual workstations linked by automaticsystems. Finally, certain production processes are simply economically “unautomatable” – forexample when quantities are too small or the product mix changes too frequently.
4
Uncertain quantity requirements
Unc
erta
inty
in p
rodu
ct m
ix
Automated production cell,not linked
Manualproduction system
Flexible modular system:add automation as needed
Fully automatedcomplete solution
Selecting the most suitable production system: the decisive factors are product quantities and variants as wellas the predictability of these requirements.
Predictable quantity requirements, high quantities
Manual, hourly rate of 30 €Manual, hourly rate of 5 €
Pick & placeTransfer system
0.03 €
0.02 €
0.01 €
0.00 €
5P
redi
ctab
le p
rodu
ct m
ix, l
ong
prod
uctio
n cy
cle
Efficient transport ensureseconomical production Each production process involvesmaterials or workpieces which aretransported from point A to pointB. However, as no value is addedto the product during transport,investments in this part of theprocess chain are usually ruled outfrom the outset. This is a seriousmistake: the manual forwarding ofparts from one station to the next,as well as the coordination ofindividual production processes,represents a critical factor in termsof time and cost. Therefore, theefficiency of a transfer system isalso a key factor in assessing theeconomic viability of a productionsystem.
Cost comparison of individualsystemsThe diagram above compares thecosts per transfer cycle of a manualmaterial transfer system, a “pick &place” solution and an automatedtransfer system. For both of theautomated solutions, the compari-son assumes a straight-line depre-ciation over a period of five yearsand 3500 operating hours per year(two-shift operation).Under these conditions, with a10 kg part weight, the manualsolution performs well with cycletimes > 35 sec – however, thisapplies only to low-wage countries.Automated transfer systems clearlyrepresent the most cost-effectivesolution when shorter cycle timesare required.
Other advantages of automatedtransfer systemsAvoiding overproduction• Transfer systems can be used to
regulate production cycles, sup-
0 10 s 20 s 30 s 40 s 50 s 60 s 70 s
port lean production flow princi-ples and ensure continuousproduction based on the volumeof customer demand.
Accelerating production• Reduces transfer and handling
time in comparison to manualtransport
Higher, more consistent productquality• Better protection of product sur-
faces and exact precision duringparts processing, due to the stableposition of the workpiece on thepallet
Flexible application range• Able to transport extremely
small, very sensitive, and evenvery large products safely
• Easily integrated into existing –even manual – production lineswithout difficulty
• Easy to expand or adapt tochanging production require-ments
■ Current situation■ Future trend
100 g 1 kg 10 kg 100 kg Product weight
Market
Current manufacturing trends leantoward extremely small, lightweight
products on the one hand, and towardheavy components and modules on
the other. Automated transfersystems can be used effectively in
both areas of production.
Cycle time
Costs per transfer cycle
■
■
■
■
Costs dependingon the cycle time
Rexroth – the “lean recipe” for your production
Regardless of industry segment, product, quantity, or manufacturing technique, Rexrothalways offers the most efficient, most cost-effective solution for your production. WhetherManual Production Systems, or automated transfer or handling systems – we have the rightproducts for every situation, and the relevant know-how to make your manufacturing leaner.
6
No two systems are the sameFor the reasons mentioned above,there is no easy answer as to whichis the most efficient transportsolution to ensure lean production.A rash decision against automationwithout a careful evaluation of its
potential benefits risks causingwaste – and this is exactly whatlean production seeks to avoid.Individual factors throughout theproduction process must be con-sidered carefully before a decisionis made – whether in favor of
manual parts transport or auto-mated parts forwarding via transferor handling systems.
7
Rexroth – everything you need for lean productionWe will gladly help you find the right systemto meet all your requirements by offeringcompletely neutral and objective support.At Rexroth, you can profit from our knowledgethat goes far beyond single-system solutions,
and from a range of products which covers allaspects of lean production. Whether manualproduction or automatic transport systems –we have the solution you need.
Increasing levels of automation in production:From manual workstations to interlinkedworkstations with EcoFlow, to the VarioFlowworkpiece pallet system and the TS 2plustransfer system
US
Germany
ABosch Rexroth Corporation
816 E. Third StreetBuchanan, MI 49107Tel. +1 800 REXROTH
+1 800 739 7684Fax +1 269 695 5363
CanadaBosch Rexroth Canada Corp.3426 Mainway DriveBurlington, Ontario L7M 1A8Tel. +1 905 335-5511Fax +1 905 335-4184
Great Britain Bosch Rexroth LimitedCromwell RoadSt. Neots, HuntingdonCambs. PE19 2ES Tel. +44 1480 223 298Fax +44 1480 470 789
AustraliaBosch Rexroth Pty. Ltd.3 Valediction RoadKings Park, NSW 2148, SydneyTel. +61 2 9831 7788Fax +61 2 9831 5553
Bosch Rexroth AG
Linear Motion and Assembly Technologies
Postfach 30 02 0770442 Stuttgart, GermanyTel. +49 711 811-30698Fax +49 711 811-30364www.boschrexroth.com/brl
www.boschrexroth-us.com
© Bosch Rexroth CorporationPrinted in U.S.A.8981 500 35409/06