Listing Quality Metrics

Anyone with access to a project can view the metrics for a CTQ added to the project.

Before you begin: View the Properties page for a quality. See Viewing Information about a CTQ.

  1. From the Categories menu, click Quality Metric.



    The columns differ depending on whether the CTQ's data type is continuous or discrete. The first metric is always the Goal metric (the one added when the metric is created).

    For each metric, the page lists these details:

    Name. The system enters numeric names for metrics. The same name is used for all metrics in a CTQ but each metric is appended with a sequential number.

    Source. A metric's source can be Goal, Predicted, Allocated, Measured, or Controlled. For a description of these metrics, see Quality Metrics and Their Sources.

    Date. The date the metric was added.

    For discrete CTQ:


    • DPMO. Defects Per Million Opportunities. The average number of defects per unit observed during an average production run divided by the number of opportunities to make a defect on the product under study during that run normalized to one million.
    • DPU. Defects Per Unit is the average number of defects observed when sampling a population. DPU = Total # of Defects / Total population
    • Sigma. NORMSINV(1-((Total Defects) / (Total Opportunities))) + 1.5

    For continuous CTQs:


    • Mean. The desired mean for the end of the project. The mean is the average data point value within a data set. To calculate the mean, add all of the individual data points then divide that figure by the total number of data points.
    • Standard Deviation. The desired standard deviation for the end of the project. Standard deviation is a statistic used to measure the variation in a distribution. Sample standard deviation is equal to the square root of (the sum of the squared deviations of the mean divided by the sample size minus 1).
    • Upper Spec Limit. The desired upper specification limit for the end of the project, as specified by the customer.
    • Lower Spec Limit. The desired lower specification limit for the end of the project, as specified by the customer.
    • Sigma. NORMSINV(1-((Total Defects) / (Total Opportunities))) + 1.5

    Originator. The username for the person who added the metric.

    Edit. Click to edit the metric. See Editing a Metric.

    . Opens the Properties page of the metric in a new window. See Viewing Metric Properties.

  2. Use the page Actions menu or toolbar to work with the projects:

    Create New. Creates a new CTQ. See Creating a Metric.

    Remove Selected. Deletes a selected metric. You can only delete the last metric. After deleting a metric, you can then edit or remove the next metric.