450 likes | 475 Views
Setup Reduction -- Creating More Production Time Dr. Richard A. Wysk rwysk@psu.edu http://www.engr.psu.edu/cim March 20, 2003. Make it better! Make it faster! Make it cheaper!. Let’s spend a few minutes and talk about how we might make things: better, faster and/or cheaper.
E N D
Setup Reduction -- Creating More Production TimeDr. Richard A. Wyskrwysk@psu.eduhttp://www.engr.psu.edu/cimMarch 20, 2003
Make it better!Make it faster!Make it cheaper! Let’s spend a few minutes and talk about how we might make things: better, faster and/or cheaper.
HIGH FLEXIBILITY TRANSFER LINE PRODUCTION CAPACITY SPECIAL SYSTEM FLEXIBLE MANUFACTURING SYSTEM VOLUME MANUFACTURING Cells STD. AND GEN. MACHINERY LOW HIGH VARIETY
Readings • Singo Shingeo, A Revolution in Manufacturing-The SMED-Single Minute Exchange of Dies-System, Productivity Press, 1981. • Chapter 18 of Computer Aided Manufacturing, Wang, H.P., Chang, T.C. and Wysk, R. A., 3rd Edition (2004 expected) http://www.engr.psu.edu/cim/active/ie450ho1.pdf
Objectives • To be able to identify internal and external process elements • To be able to apply methods improvements techniques to manufacturing • To calculate/measure the various Production Time Elements • To be able to apply the techniques of set-up reduction
ExerciseReadiness Assessment Test A.K.A. RAT Complete the RAT for this module before you meet to discuss this for class. What set up reduction activities did you select as having value added to you for personal benefit?
How long does it take to produce something? • It is not unusual for the processing time to be a very small part of the time required to make a component. • Order materials • Accumulate parts • Setup machine
JIT -- Speed is everything! Some Just in time models Buying bread Buying milk Buying “take-out”
Exercise • What are the most important factors that contribute to the production time (average time required to produce a single unit/product)?
In Industry Between .05% and 5% of the time Value is being added to a product
What are the Value added activities at PSU Inc.? Receiving -> Material handling -> Machining -> Assembling -> Packaging
Are we really adding value What percent of the time are the machines producing good product? What percent of the time are the moving and setting up?
Producing a product Production time (per lot) = setup time (per lot) + manufacturing time (per lot)
Producing a product Manufacturing time (per piece) = material handling and locating time (per piece) + manufacturing time (per piece)
t =S(t + t )/ Nb + tset / Nt j j + t + t + t j P m c i setup L/UL A j Product time (per piece) Total production time = S (set up time + load/unload time + processing time + idle time + tool change time) + initial set up time
t =S(t + t )/ Nb + tset / Nt j j + t + t + t j P m c i setup L/UL A j j t setup j the time required to load and unload a product for feature operation j (chuck, fixture, etc..) t j t the machining/processing time for feature j m t tool change time/part c t idle time due to scheduling control i t the time required for initial setup, e.g., fixture design, process planning, etc.) set the time required for setup for an operation (load fixture, retrieve tooling , etc.) L/UL
t t t = t t + + + p m Ch / N b set l/ul Production time per piece • The cost associated with new tooling is also a key consideration • for the designer. • For low and medium volume products, the cost associated with • tooling and setup can dominate the total product cost.
/ / + + C n C = t n C C p p mo t setup p/t bt • The product cost can be expressed as: Production cost per piece, Cp
where Cmo is the cost of machine and operator/hour Ct is the perishable tooling cost np/t is the number of pieces that can be produced per tool Csetup is the setup resource cost for the part (fixture, jig, steady-rest, etc) nbtis the total number of parts to be produced
Simple CNC Example • New batch of parts arrives • Change over tools for the batch • Set offsets for new tools • Load NC program • Validate • Run parts • Load part onto machine • Cycle start and wait • Unload and visually inspect (adjust if necessary) Setup time per lot Material handling and loading time per piece
Graphically it looks like TOTAL TIME TO PRODUCE A LOT OF PRODUCT SETTING UP THE MACHINE RUNNING THE MACHINE AND OFF-LINE MEASUREMENT This can be > 30% of the TOTAL TIME TO PRODUCE A LOT
This can be > 30% of the TOTAL TIME TO PRODUCE A LOT A look at SETUP SETTING UP THE MACHINE Setup consists of activities that must be performed on the machine (these are called Internal Elements), and elements that can be performed off-line or while the machine is producing a product (these are called External Elements)
Rapid Tool Change-over Setup consists of • Internal Elements - Elements that must be performed on the machine itself • External Elements - Elements that can be performed “off-line”
A look at SETUP (cont’d) SETTING UP THE MACHINE Internal Elements External Elements These External Elements can be completed while the machine is producing good product. For instance, we can clean a die set after the machine comes up. We can preassemble components for a setup.
A look at SETUP (cont’d) SETTING UP THE MACHINE Internal Elements External Elements RUNNING THE MACHINE If the External Elements are performed while the machine is producing good parts then we can reduce the TOTAL PRODUCTION TIME by starting production earlier.
Premise for SMED Idle time waiting for materials or other resources Set up time where machine is down while operators prepares for next activity Processing time - adding value to raw materials
Graphically it looks like TOTAL TIME TO PRODUCE A LOT OF PRODUCT SAVINGS SETTING UP THE MACHINE RUNNING THE MACHINE AND OFF-LINE MEASUREMENT Production Time gained
Premise for SMED Methods improvements Idle time waiting for materials or other resources Set up time where machine is down while operators prepares for next activity Processing time - adding value to raw materials
Exercise (5 minutes) As an individual, describe a process that you know well (from work, food preparation, office activities…) Identify the internal and external elements for setup or work changeover.
Methods Improvement • Standard ways to improve setup efficiency • Power tools • Collets and quick-change fixtures • 2nd set of fixtures and tools • Setup layout • Setup accumulation
Make the tool part of the screw device -- you don’t need a tool, and this will save time in disassembling and reassembling the tooling and fixturing!
Reduce the amount of turns required in order to activate the screw.
Areas with potential benefit • Screws and screw fasteners • Tedious manual activities • Power tools can be appropriate • Connectors • Others????
Exercise As an individual, describe what methods, improvements, you could make to the setup/change over activity for the Case production system or some other system that you are familiar with?
SMED is employee driven • Train Area supervisors and operators • Some implementation with outside consultant • Most implementation within your company