Management Tools: Problem Solving 270

80/20 rule

The belief that 80 percent of errors in a system are caused by only 20 percent of the inputs. Also known as the Pareto principle.

average

The statistical norm or expected value that falls within the middle of a distribution pattern.

cause and effect

Two related events in which one event causes the other to occur.

cause and effect diagram

Also known as a fishbone diagram. A fishbone-shaped diagram used to identify the cause of a specific problem.

central location

The middle of a histogram.

check sheet

A visual tool for tracking data and making decisions by placing tic marks into different cells to create a graphic representation of the data being tracked.

continuous data

Information that can be measured on a scale and compared with other data. An example of continuous data is cycle time, which can be measured and compared to show differences between different machines, operators, or shifts.

continuous improvement

The efforts of an organization to constantly measure the effectiveness of its processes and strive to meet more difficult objectives to satisfy customers.

control chart

A chart used to show trends in data over a period of time. Points are plotted on the chart and connected by a line to show an upward or downward trend.

control limit

A boundary for a sample average that defines the limits on process capability.

correlation

A situation occuring when data points on a scatter diagram are close enough to form a line.

current state

A visual tool that documents the current condition of a manufacturing environment. A current state value stream map captures all of the details of manufacturing processes just as they exist at the moment the map is produced, including any flaws or errors.

cycle

The journey of a part or process from the beginning to the end of a work unit.

cycle time

The actual time it takes to perform a task or process and forward it to the next step. One of the major goals of lean is to match cycle time to the customer's requirements.

discrete data

Information that represents a characteristic or an individual "count." An example of discrete data is a count of the number of good parts or defects.

failure modes and effects analysis

A document used to identify and assess potential failure modes in a product or process. The FMEA includes potential causes and effects of failure along with a prediction of the likelihood of their occurrence.

fishbone diagram

Also known as a cause and effect diagram. A fishbone-shaped diagram used to identify the cause of a specific problem.

Five Whys

A problem solving method in which a person repeatedly asks "Why?" until the root cause of a problem is identified.

flow chart

A visual representation of the steps required to manufacture a product.

future state

A visual tool that shows how a value stream can look after improvements have been implemented. A future-state value stream map is an ideal view of a value stream and represents the goal of a lean initiative.

histogram

A visual graph that shows the frequency of a range of variables. Typically histograms are used to measure distribution patterns. A normal histogram should be bell-shaped.

ideal state

A type of value stream map that shows what the value stream would look like after all known lean methods have been incorporated. The ideal state map identifies opportunities for improvement in the value stream.

information symbols

Icons on a value stream map that represent the form, flow, and direction of communication and data.

Ishikawa diagram

Also known as a cause and effect diagram. A fishbone-shaped diagram used to identify the cause of a specific problem.

lead time

The time it takes one piece to move all the way through a process or value stream, from start to finish.

lean

An approach to creating products and services that seeks to reduce the cycle time of processes, increase flexibility, and improve quality. Lean initiatives help to eliminate waste in all its forms.

line balancing

Adjusting processes so that all tasks performed in a cell are performed within the same amount of time. For example, if the first step takes 60 seconds, the second and third steps should also take 60 seconds.

machinery

The part of a fishbone diagram that represents the potential for error due to machine performance.

man/woman

The part of a fishbone diagram that represents the potential for human error.

material symbols

Icons on a value stream map that represent the origin, location, and movement of raw materials and parts within the system.

materials

The part of a fishbone diagram that represents the potential for error due to quality issues with materials in the process.

methods

The part of a fishbone diagram that represents the potential for error or outdated information in work instructions and practices.

metric

Any form of measurement. Metrics are important in lean because everything that can be measured can be improved.

negative correlation

A situation occuring when x-y values for the data points go from high to low on a scatter diagram.

no correlation

Data points on a scatter diagram that are too loosely clustered to suggest a line.

Pareto chart

A vertical bar chart used to signify the importance of one or more groups of data in relation to one or more other groups of data.

Pareto principle

The belief that 80 percent of errors in a system are caused by only 20 percent of the inputs. Also known as the 80/20 rule.

positive correlation

A situation occuring when x-y values for the data points go from low to high on a scatter diagram.

problem statement

A description of the issues that need to be addressed. The problem statement appears at the head of the fishbone diagram.

process map

A simple diagram that uses symbols to represent steps and machines, with arrows indicating the flow of parts among them.

process symbols

Icons on a value stream map that represent the actions that take place or the locations where processes occur.

processes

The series of activities required to complete a product or provide a service to a customer.

product family

Products that are grouped together based on the fact that they are created by the same machines or processes.

real time

Current or present time.

root cause

The underlying cause of a problem. It is important to identify the root cause of a problem before taking corrective action.

root cause analysis

A study undertaken to find the first or underlying cause of a problem. Root cause analysis involves the collection and study of data to determine a true cause to a problem.

scatter diagram

A chart that uses the clustering of plotted points to determine if the increase or decrease of one variable is related to an increase or decrease in the other variable.

spaghetti diagram

A type of flow chart used for showing inefficient floor layouts and excessive distances and travel time between tasks as the product, service, or information is pushed from one process to the next.

spread

How different the values are from each other and from the middle of a histogram.

statistical process control

A method of measuring and controlling the processes that yield a product. In SPC, statistics are used to collect sample data and allow predictions of the overall process.

statistics

Data that can be represented numerically and used as a representative sample of a larger group of data.

takt time

The rate at which the customer requires a part to be produced. Cycle time should always be adjusted until it meets takt time.

timeline

The part of a value stream map located below process and materials. The timeline contrasts cycle time with lead time and is one of the most revealing areas of the value stream map.

value

A real or perceived quality that satisfies the needs and wants of a customer. Value includes the features of a product, as well as other qualities associated with the product.

value stream

The series of activities within a supply chain that add value from the perception of the customer. The value stream involves the series of activities needed to create a product.

value stream map

A sophisticated flow charting method that uses symbols, metrics, and arrows to help visualize processes and track performance. This method helps determine which steps of a process add value and which do not.

variation

Any change from what is normal and consistent. Variation is undesirable in lean.

waste

Anything that does not add value to a product. The goal of lean is to eliminate waste.

work flow analysis

The process of examining the physical layout of a process and determining ways to improve flow by reducing travel distances, eliminating redundancies, and improving communication and quality.