Synchronous Manufacturing

Synchronous Manufacturing andSynchronous Manufacturing andthe Theory of Constraintsthe Theory of Constraints

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Synchronous Manufacturing and the Theory of Constraints

• The Goal of the firm

• The hockey-stick phenomenon

• Performance measurement

• Capacity and flow issues

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Some Capacity Related Terminology

• Capacity– Available time for production

• Bottleneck– Capacity is less than demand placed on resource

• Nonbottleneck– Capacity is greater than demand placed on

resource• Capacity-constrained resource (CCR)

– Capacity is close to demand placed on resource

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Bottlenecks and CCRsFlow-Control Situations

• A bottleneck – (1) with no setup required when changing from

one product to another– (2) with setup times required to change from one

product to another• A capacity constrained resource (CCR)

– (3) with no setup required to change from one product to another

– (4) with setup time required when changing from one product to another

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What’s Going to Happen?

X Y Market

Case A

X YBottleneck Nonbottleneck

Demand/month 200 units 200 unitsProcess time/unit 1 hour 45 minsAvail. time/month 200 hours 200 hours

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Y X Market

Case B



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X Y

Assembly

MarketCase C



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X Y

Market MarketCase D



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Components of Production Cycle Time

• Setup time– the time that a part spends waiting for a

resource to be set up to work on this same part• Process time

– the time that the part is being processed• Queue time

– the time that a part waits for a resource while the resource is busy with something else

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Components of Production Cycle Time

• Wait time– the time that a part waits not for a resource but

for another part so that they can be assembled together

• Idle time– the unused time

• the cycle time less the sum of the setup time, processing time, queue time, and wait time

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Saving Time

Bottleneck Nonbottleneck

What are the consequences of saving time at each process?

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Drum, Buffer, Rope

A B C D E F

Bottleneck (Drum)

Inventorybuffer

(time buffer)Communication

(rope)

Market

Module 2

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Goldratt Proclaims

The goal of a firm is to make money.

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The Hockey Stick Phenomenon

• The end-of-period rush!

Period1 2 3 4

Output($)

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Performance MeasurementFinancial

• Net profit– an absolute measurement in dollars

• Return on investment– a relative measure based on investment

• Cash flow– a survival measurement

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Performance MeasurementOperational

• 1. Throughput– the rate at which money is generated by the

system through sales• 2. Inventory

– all the money that the system has invested in purchasing things it intends to sell

• 3. Operating expenses– all the money that the system spends to turn

inventory into throughput

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Productivity• Does not guarantee profitability

– Has throughput increased?

– Has inventory decreased?

– Have operational expenses decreased?

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Unbalanced Capacity• Earlier, we discussed balancing assembly

lines.

– The goal was constant cycle time across all stations

• Synchronous manufacturing views constant workstation capacity as a bad decision.

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The Statistics of Dependent Events

• Rather than balancing capacities, the flow of product through the system should be balanced

Process Time (B)Process Time (A)

Thank You

Gopakumar S Binisha Manu

Documents

Synchronous Manufacturing