Reduce Manufacturing Costs by CT Effects

The key to reducing production costs is found in CT effects.
So what exactly are CT effects?

Download the CT Effects Study

Overview of the Line

This case example involves onboard assembly and test lines with four steps. The cycle time of Step 3, which was taking the longest among them, was reduced.

System specifications

• Number of air cylinders = 8 units
  • Unit 1 - Moves the work table
  • Unit 2 - Press-fitts the connector
  • Unit 3 - Electric continuity test
  • Units 4, 5, 6 - Stamping
  • Unit 7 - Connection of wires for inspection
  • Unit 8 - Stops the work table at the midpoint

• Product types supported = 10 types (25 types can be supported with 3 lines.)
• Cycle time = 14.0 seconds

Overview of the System

It is a simple semi-automatic system that conducts a performance test of onboard sensors. When the operator sets the work part and presses the start switch, the work table moves forward toward the back of the system. Once steps 1, press-fitting of the connector (assembly): 2, electrical continuity test: and 3, stamping (PASS stamp) are completed, the table comes back to the forward position.

Significant Improvement of Production Efficiency through Motorization

With the air cylinder system, the work table could not be operated faster because it would have increased the shock upon stopping. With the ROBO Cylinder system, on the other hand, the maximum speed can be increased because the actuator stops without generating shock. In addition, the ROBO Cylinder system starts quicker than the air cylinder system, which enabled significant reduction of the cycle time. Work table operation takes 1.8 seconds less.

With the air cylinder system, an automatic switch was used to determine whether the work part had been pressed to the specified position, which made the operation unstable and required 4 seconds for the press-fitting action to ensure quality. With the ROBO Cylinder system, on the other hand, push-motion operation can be performed using the zone function and consequently the press-fitting time was successfully reduced by 2 seconds. Push-motion operation takes 2 seconds less.

Number of lines and operators required to produce 5,000 pieces in one 7.5-hour day (27,000 sec.) Air cylinder system ROBO Cylinder system Cycle time 14.0 sec. 10.2 sec. Number of work parts that can be produced per line in one 7.5-hr day (27,000 seconds) 27,000 seconds / 14.0 seconds = 1,929 pcs 27,000 seconds / 10.2 seconds = 2,647 pcs Number of lines required 5,000 pcs / 1,929 pcs = 2.6 -> 3 lines 5,000 pcs / 2,647 pcs = 1.9 -> 2 lines Number of operators required (one operator per line) 1 operator x 3 lines = 3 operators 1 operator x 2 lines = 2 operators Other Conditions Air cylinder equipment cost for one unit $55,600 ROBO Cylinder equipment cost for one unit $61,100 Labor cost for one person $72,200/year Increased Profits through Motorization Year 1 Equipment cost: Reduced from 3 to 2 lines Labor cost: Reduced from 3 to 2 operators $55,600 x 3 lines – $61,100 x 2 lines = $44,600 $72,200 x (3 - 2 operators) = $72,200 x 1 = $72,200 __________________________________________ Sub-total: $116,800 Year 2 Labor cost: Reduced from 3 to 2 operators $72,200 Year 3 Labor cost: Reduced from 3 to 2 operators $72,200 3-year total: $261,200 As illustrated above, the reduction of cycle time through the motorization of the air cylinder system yielded a profit of $116,800 for the first year, and $72,200 for the second and subsequent years, resulting in a 3-year total of $261,200.

 
* Based on case study in IAI Japan. * Exchange Rate: 1 (USD) = 100 (Japanese Yen)

 

Download the CT Effects Study pdf