IND 400 Chapter 2-3: IND400- Chapter 2-3 Critical Calculations
2 May 2018
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Determining Takt Time (Plant Rate) – R value
rate at which operations, processes, parts, components & so on must run to meet the
production goal.
• Things you need to know to calculate it:
Production goal
Time allotted for the production of these units ( ie. 2 8hour shifts)
Nonproductive time that takes away from production time (ie. Breaks)
General knowledge of overall plant efficiency as determined by unplanned
downtimes, inventory stock-outs, aseteeis… et.
• Example of TAKT time calculation:
Need to produce and ship 1,000 units of product demand
In an 8-hour shift production time
30 for lunch, 10 for break, and 8 min for team meetings during each shift
unproductive time
plant is operating at 90 percent efficiency plant efficiency
Takt time = Ta ri i
Ta aiy a in minutes/ unit
1/ Takt time = #units/ min.
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find more resources at oneclass.com
Calculating Scrap and Rework Rates
• Quality and production departments have historical data that indicate the
level of rework and scrap for each operation.
Considerations in TAKT time calculations:
scrap and rework rates
the need for spare or replacement parts
In the preceding example:
• the press operation produces 3% scrap
• Therefore, to end up with 1,000 finished wagon bodies, you must start with a larger
number so that after scrapping 3 percent, you will have 1000 good parts
• If a job takes 1.000 standard minute to produce (Figure 3–1), you can produce 60 pieces per hour,
and it will take .01667 hour to make one unit or 16.67 hours to make 1,000 units.
Rounding Rules
1. The decimal minute (always in three decimal places, e.g., .001)
2. Pieces per hour (rounded off to whole numbers, unless less than 10 per hour)
3. Hours per piece (always in five decimal places, e.g., .00001)
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find more resources at oneclass.com
HOW MANY MACHINES DO WE NEED?
Depends on: how many pieces do u need to make per shift &
▪ How much time does it take to make one part? (time std)
1)
__ Number of product to be produced _ =
Effective minutes per shift * Performance Rating
= 2000 wagons__________________ Ideally Performance Rating=1
( 8hour/shift*60min/hr -50min breaks) (0.74)
= parts/ min
For min/ parts (takt time/ plant rate) flip numerator and denominator
Machines = Time standard
Plant rate
= Time standard =0.4 min/unit
Plant rate= 0.161 min/unit
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Determining takt time (plant rate) r value. Rate at which operations, processes, parts, components & so on must run to meet the production goal: things you need to know to calculate it: Time allotted for the production of these units ( ie. 2 8hour shifts) Nonproductive time that takes away from production time (ie. breaks) General knowledge of overall plant efficiency as determined by unplanned downtimes, inventory stock-outs, a(cid:271)se(cid:374)teeis(cid:373) et(cid:272): example of takt time calculation: Need to produce and ship 1,000 units of product demand. In an 8-hour shift production time. 30 for lunch, 10 for break, and 8 min for team meetings during each shift unproductive time. Plant is operating at 90 percent efficiency plant efficiency. Calculating scrap and rework rates: quality and production departments have historical data that indicate the level of rework and scrap for each operation. The need for spare or replacement parts.
