Process Terminology

cycle time: the average time between completion of successive units

bottleneck: the factor which limits production

work in process:  inventory in the system

manufacturing lead time (throughput time): length of time spent in the process

Little's Law: MLT = WIP * CT

throughput time = work in process x cycle time

idle time: time when useful work is not being performed

balance/imbalance: perfect balance; no idle time

lot size: number of units of like product produced at once

setup time: time between good units of succeeding products

direct labor content: work contained in the product

direct labor utilization: direct labor content/total available labor time

total available labor time includes idle time

process: transform inputs into outputs

outputs: goods or service

use process flow diagram to illustrate process

Notice different setups with same equipment

(figure 1: parallel lines)

(figure 2: tasks into parallel, not entire lines)

Determining capacity: depends on situation

Capacity: maximum output per unit of time

Types of Inputs

• labor
• materials
• energy
• capital
• productivity used to measure effectiveness

• good or service
• hard to put value on

• something that adds value
• flows: physical, movement; information, information about the product

• holding of inventory
• raw material, work in process (WIP), finished goods

capacity

easy to define and hard to measure

theoretical and effective capacities

rarely a fixed quantity

relates value of output to value of input

75% efficient, 75% of input transferred to output

profitability, utilization

how long it would take to change to produce another product

time to switch line from one product to another

fitness for use

conformance to specifications