EMBA-2, BUP Major Asad EO - 702 Chapter 5: Process Analysis.

EMBA-2, BUP

Major Asad

EO - 702

Chapter 5:

Process Analysis

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Process Analysis

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Process capacity - of the process is its maximum output rate, measured in units produced per unit of time. The capacity of a series of tasks is determined by the lowest capacity task in the string.

Capacity utilization - the percentage of the process capacity that actually is being used.

Cycle time - the time between successive units as they are output from the process.

Idle time - time when no activity is being performed.

Process Analysis Terms

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Process AnalysisProcess analysis generally involves the fol tasks: Define the process boundaries Construct a process flow diagram Determine the capacity of each step Identify the bottleneck Evaluate further limitations Analyze, make decisions and to improve process.

Process Flowcharting Process flowcharting is the use of a diagram to present

the major elements of a process

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Other Types of Processes Make-to-order -Only activated in response to an actual

order. Here both work-in-process and finished goods inventory kept to a minimum

Make-to-stock-Process activated to meet expected or forecast demand, Here, customer orders are served from target stocking level

Hybrid -Combines the feature of both make-to-order and make-to-stock.

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Types of Processes 1. Single-stage Process – 2. Multi-stage Process –

Blocking - occurs when an activity becomes idle because the next downstream activity is not ready to take it.

Starvation - occurs when a downstream activity is idle with no inputs to process because of upstream delays.

Both starvation and blocking can be reduced by adding buffers that hold inventory between activities.

Buffer- refers to a storage area between stages where the output of a stage is placed prior to being used in a downstream stage

Bottleneck -occurs when the limited capacity of a process causes work to pile up or become unevenly distributed in the flow of a process

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Measuring Process Performance Setup time: The time required to prepare the equipment

to perform an activity on a batch of units. Set-up time can be reduced on a per unit basis by increasing the batch size.

Run time : Time require to produce a batch of parts. Operation time = Setup time + Run time Throughput time ( or Flow time or lead time) - the

average time that a unit requires to flow through the process from the entry point to the exit point. The flow time is the length of the longest path through the process.

Throughput rate (also known as flow rate ) - the average rate at which units flow past a specific point in the process. The maximum throughput rate is the process capacity.

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Measuring Process Performance

Throughput rate = 1 / cycle time

Pacing -Refers to the fixed timing of the movement of items through the process

Value-added time – The time in which useful work is actually being done on the unit.

Process Velocity or Throughput Ratio = Throughput time / Value-added time

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Measuring Process Performance

Little’s Law Throughput time = WIP / Throughput Rate

Estimates a mathematical relationship between Throughput rate, Throughput time and amount of work in process (WIP) inventory.

Assumption : process is operating at steady rate.

Usefulness : help to diagnosis the performance of process.

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Process ImprovementImprovements in cost, quality, flexibility, and speed arecommonly sought.

Add additional resources to increase capacity of the bottleneck.

Improve the efficiency of the bottleneck activity Minimize non-value adding activities - decreases cost,

reduces lead time. Change the sequence of activities. Redesign the product for better manufacturability - can

improve several or all process performance measures. Flexibility can be improved by outsourcing certain

activities.

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Midterm-1On

Next Saturday20 Feb 2010At 0630 p.m.