OTM 300 Chapter 3

Lead Time

The time between when an order is placed and when it is filled. Process lead time is frequently used as an alternative term for flow time.

Time required to produce a given quantity X starting with an empty system

The time it takes a process with no inventory to produce a given quantity.

Time through the empty system

The time it takes the first flow unit to flow through an empty process; that is, a process that has no inventory.

Bottleneck

This determines the process capacity.

Inventory

This is a mismatch between supply and demand.

Processing time

Time to carry out all activities for a flow unit at one resource.

Empty Process

Time to produce X units with a ________ is (time through empty system) + ((X-1) * (Cycle time))

cycle time

1/flow rate

Process Flow Diagram

A graphical way to describe the process.

Resource

A group of people and equipment that transforms inputs into outputs.

Machine-paced

A process in which all steps are connected through a conveyor belt and all of the steps must work at the same rate even if some of them have more capacity than others.

Worker-paced

A process line in which each resource is free to work at its own pace: if the first resource finishes before the next one is ready to accept the flow unit, then the first resource puts the completed flow unit in the inventory between the two resources.

Process Analysis

A rigorous framework for understanding the detailed operations of a business. Among other things, the process analysis determines how many flow units can be processed per unit of time and how busy the resources of the process are.

Throughput

A synonym for flow rate, the number of flow units flowing through the process per unit of time.

Cycle Time

Captures the "rhythm" of the operation.

Utilization of a resource

Flow Rate/Capacity of resource

Buffer Inventory

Flow units waiting in the process without being worked on are often referred to as ___

Flow Rate

Found by looking at the minimum between demand and capacity.

True

If cycle time goes up, then lead time will go up (true or false)

Supply Constrained

If the process is _____ then the flow rate will equal capacity (100% utilization).

Triangles

Meant to depict inventory location

Arrows

Meant to depict movement of flow units.

Box

Meant to depict resources

Bottleneck

Resource with the lowest capacity in the process.

Triangles

Shape used to represent flow units that are waiting in a system.

Flow Unit

The basic unit that moves through a process.

Capacity-Constrained

The case in which demand exceeds supply and the flow rate is equal to process capacity.

Demand-Constrained

The case in which process capacity exceeds demand and this the flow rate is equal to the demand rate.

Demand Constrained

The case in which the flow rate will be less than capacity.

Process Capacity

The maximum flow rate a process can provide per unit of time. This determines the maximum supply of the process. The process capacity is the smallest capacity of all resources in the process.

Capacity

The maximum number of flow units that can flow through that resource per unit of time.

Demand Rate

The number of flow units that customers want per unit of time.

Upstream

The parts of the process that are at the beginning of the process flow.

Downstream

The parts of the process that are at the end of the process flow.

Utilization

The ratio between the flow rate (how fast the process is currently operating) and the process capacity (capturing how fast the process could be operating if there was sufficient demand). Note that utilization can be defined at the level of an individual resource or at the level of the entire process.

Cycle Time

The time between completing two consecutive flow units.

Processing Time

The time it takes a resource to complete one flow unit.

Capacity Constrained

When the flow rate is less than the demand rate. Bottleneck will be working at 100% capacity.

Utilization of a process

flow rate/process capacity

Capacity of a Resource

number of workers at resource/ processing time.

Full system

time to produce X units with a __________ is X * Cycle time