SMC chapter 6s
Identify the true statements about a histogram. (Check all that apply.)
- An analyst must determine the number of ranges or categories for grouping the data of a histogram. - To create a histogram, at least 30 observations are necessary. - The number of ranges in a histogram is typically between 5 and 20.
scatter diagrams cause and effect analysi check sheets pereto analysis
- Determine if two variables are related to each other (whether the two variables move together in some predictable manner) - Uncovers possible contributors to an observed problem and to facilitate group brainstorming - Identify the frequency and location of problem causes - Identifies the most critical (relatively frequent) causes of problems
Identify the steps that are used in Pareto analysis. (Check all that apply.)
- Gather the data and calculate the frequency of observations in each category for an appropriate time period. - Identify categories about which to collect information. - Present the data graphically and identify the vital few categories that account for most of the variation. - Sort the categories in descending order based on their percentages.
process flow analysis process capability analysis process control taguchi method
- Graphically displays and analyzes the steps in a process - Predicts the conformance quality of a product by comparing its specification range to the range of its process variability - Monitors process outputs and determines whether a process is operating according to normally expected limits - Evaluates and understands the effects of different factors on process outputs
Identify the true statements about a cause-and-effect diagram. (Check all that apply.)
- It is best developed by a group of people who know the root cause of a problem without any data. - It shows how the various factors in a problem interact with each other to cause the observed problems. - It is useful as a brainstorming tools. - It helps to uncover the logic chain that leads from the root causes of a problem to its effects.
Identify the characteristics of a process control chart. (Check all that apply.)
- It is used to regularly monitor the output of a process to ensure that output lies within the expected variation limits of the process. - It plots values for samples of process output collected over time. - It compares summary statistics for samples of output against predetermined process limits.
Identify the steps that are used to build an xx − R chart. (Check all that apply.)
- Plot new xx and R values on the control charts. - Calculate the mean range. - Calculate the sample mean for each sample. - Calculate the overall "grand" mean. - Find the range for each sample. - Compute control limits and construct the charts. - Collect data to calculate control limits
Identify the true statements about process control charts. (Check all that apply.)
- Process control charts are similar to process capability studies in that both tools evaluate the variability of processes. - The terms statistical process control (SPC) and process control charts are often used synonymously.
identify the problem to examine identify the major categories of cause identify more specific casues circle likely causes verify the causees
- State the symptom or the effect (outcome) that must be explained in the form of a variance statement. Placed on the extreme right of the diagram, an arrow is drawn from left to right. This arrow denotes the root effect—the link between the effect and the root causes. - Represent the major reasons for problems as main branches off the problem arrow, indicating the name of each category at the end of its branch. - On each main branch, place smaller branches to represent detailed causes that could contribute to the primary categories of causes. For each detailed cause, ever-smaller branches represent still more specific and detailed causes. - After the diagram has been developed to show all potential causes, review all of the causes and identify the most likely ones. Further analysis and data collection can then focus on those causes. - After identifying the most likely causes, use other tools to ensure they really are the root cause of the problem.
center width shape
- The theoretical or desired mean of a distribution should fall under this. - It indicates the unpredictability of the process. - It indicates the degree of variability in outcomes and the types of factors that may be influencing the overall distribution.
trends runs hugging periodicity
- These occur when successive points in a control chart seem to fall along a line moving either upward or downward. - These indicate the systematic changes in a process that require attention. - This occurs when various points appear so closely grouped around the central line of a control chart that they seem to show no variation. - This occurs when the plotted points in a control chart show the same pattern of change over equal intervals.
Bell-shaped double or twin peaked plateau comb skewed
- This is centered and symmetrical about the mean of a distribution. - This often indicates that two normal distributions have been combined (signifying that there may be more than one process at work). - This is often the result of combining multiple data sets, where the data sets themselves are moving. - This typically occurs if there are errors in the process, faulty measurements, error in data collection, rounding errors, or poor grouping of data into categories. - This is a symmetrical pattern of data, typically indicating that there is some limit that is restraining a process on one side of the distribution. This can be either positive or negative.
In a process, the design length of a shaft is 1500 meters with a tolerance of ± 20 meters. Identify the length range of the shaft that will make the process capable.
1485 meters to 1515 meters
is a graphical representation of the distribution of values.
A histogram
is a graphic illustration of the relationship between two variables.
A scatter diagram
is used to monitor the mean and range values for samples of variable data describing a process output.
An xx − R chart
Identify the various names of the quality improvement tool illustrated in the given image. (Check all that apply.)
Fishbone diagram Ishikawa chart Cause-and-effect diagram
Identify the quality tool that is used to uncover underlying patterns (range and frequency) in data variability.
Histogram
Identify the steps that are used in the process of building a cause-and-effect diagram. (Check all that apply.)
Identify the problem to examine. Identify the major categories of causes. Verify the causes. Identify more specific causes. Circle likely causes.
x-r np p u c
Measurement (inches, mm), volume, product weight, power consumed Number of defects Fraction defective Number of pin holes in pieces of plated sheet, differing in area (area/volume is not fixed) Number of pin holes in a specified area (area is fixed)
is a tool for assessing the ability of a process to consistently meet or exceed a product's design specifications.
Process capability analysis
Define variable data.
They are data that measure quantifiable or numerical conditions.
Identify the conditions in control charts that indicate a need for intervention in a process. (Check all that apply.)
Trends Hugging Runs Periodicity
The given figure illustrates
a check sheet
Pareto analysis is used to
identify the most critical (most frequent) causes of problems
Cpk
is a measure of process capability that compares the specification width with the process width that is adjusted for lack of centering
A check sheet
is a simple tool used to collect, organize, and display data to reveal patterns.
Attribute data
measure qualitative dimensions or conditions.
is a statistical tool used to monitor a process output to detect significant changes.
process control chart
In process capability analysis, , denoted by P, denotes the actual range of outcomes generated by the production process itself.
process width
A cause-and-effect diagram
shows the causes of certain outcomes.
Identify the formula that is used to calculate the capability index of a process.
specificationwidthprocesswidthspecificationwidthprocesswidth the only one in a fraction
In process capability analysis, a process is termed not capable when
the process output is longer or shorter than the range that the specification allows
A quality improvement tool measures data such as speed, acceleration, and direction of a moving object to determine the cause of a problem in a certain process. In this scenario, the data being measured is an illustration of
variable data