Specify variables for Create Stability Study Worksheet

Stat > Regression > Stability Study > Create Stability Study Worksheet

Select the option that best describes how you want to collect data for your stability study.

Test times in numeric format, at varying intervals

Complete the following steps if the test times represent the age of the product, and you plan to vary the amount of time between tests. For example, you can enter 0, 3, and 9 to indicate that samples are analyzed when the product is first created (Time 0), when the product is 3 months old, and when the product is 9 months old.

  1. From the drop-down list, select Test times in numeric format, at varying intervals.
  2. From Number of test times, select the number of times that you will test each batch during the study.
  3. From Unit of time, enter the unit of time you will use to measure the intervals. The most common units of time are days, months, and years.
  4. Under Month (or other unit of time), in the table, enter the times at which you will test the product.
  5. From Number of batches, select the number of batches that you will test for the study.
  6. Under Batch Name, in the table, change the labels that identify the batches.
  7. From Number of samples from each batch at each time (repeats), select the number of individual samples that you will test from each batch at each time.

Test times in numeric format, at constant intervals

Complete the following steps if the test times represent the age of the product, and you do not plan to vary the amount of time between tests. For example, you can specify that samples are analyzed when the product is created (Time 0), and then every month for 2 years, for a total of 25 test times.

  1. From the drop-down list, select Test times in numeric format, at constant intervals.
  2. From Number of test times, select the number of times that you will test each batch during the study.
  3. In Starting time, enter the age of the product at the first test time. For example, 0 indicates that you will test the product as soon as you create it.
  4. In Interval length, enter the amount of time between tests. For example, you can enter 2 to indicate that the test times are 2 months apart.
  5. From Unit of time, enter the unit of time you will use to measure the intervals. The most common units of time are days, months, and years.
  6. From Number of batches, select the number of batches that you will test for the study.
  7. Under Batch Name, in the table, change the labels that identify the batches.
  8. From Number of samples from each batch at each time (repeats), select the number of individual samples that you will test from each batch at each time.

Test times in date/time format, at varying intervals

Complete the following steps to enter the date of each test and to vary the amount of time between tests. For example, you can enter a series of dates that start with 1/1/2017, 4/1/2017, 10/1/2017.

  1. From the drop-down list, select Test times in date/time format, at varying intervals.
  2. From Number of test times, select the number of times that you will test each batch during the study.
  3. In Starting date, enter the date of the first test. This is usually the day that you create the product.
  4. Under Date, in the table, change the dates that identify the intervals.
  5. From Number of batches, select the number of batches that you will test for the study.
  6. Under Batch Name, in the table, change the labels that identify the batches.
  7. From Number of samples from each batch at each time (repeats), select the number of individual samples that you will test from each batch at each time.

Test times in date/time format, at constant intervals

Complete the following steps to enter the date of each test and to specify the same amount of time between tests. For example, use this option if you analyze samples on 1/1/2017, and then test products every month for 2 years, for a total of 25 test times.

  1. From the drop-down list, select Test times in date/time format, at constant intervals.
  2. From Number of test times, select the number of times that you will test each batch during the study.
  3. In Starting time, enter the date of the first test. This is usually the day that you create the product.
  4. In Interval length, enter the amount of time between tests. For example, you can enter 4 to indicate that the test times are 4 months apart.
  5. From Unit of time, enter the unit of time you will use to measure the intervals. The most common units of time are days, months, and years.
  6. From Number of batches, select the number of batches that you will test for the study.
  7. Under Batch Name, in the table, change the labels that identify the batches.
  8. From Number of samples from each batch at each time (repeats), select the number of individual samples that you will test from each batch at each time.

Use test times from columns in worksheet

Complete the following steps to enter test times that are stored in columns in the worksheet. Each column must contain the test times for 1 batch.

  1. From the drop-down list, select Use test times from columns in worksheet.
  2. In Test times (one column per batch), enter the columns that contain the data that you want to analyze.
  3. From Number of samples from each batch at each time (repeats), select the number of individual samples that you will test from each batch at each time.
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