LIMS.eu

Specification Limits in Practice

For specification limits to be applied during measurement entry, the corresponding specification must be selected for the sample.
The specification limits are then integrated into the LDB view where you enter measured values, and the measured values are automatically compared against the specification limits.

Benefits in daily work:

• At a glance, you can see whether measured values are within the valid range. Deviating measured values are automatically highlighted in your chosen color (red, orange, green).
• The marking of deviating measured values is possible both when entering measured values and in the report.
• Immediate response to critical values is possible.

The following describes how to define specification limits/reference ranges:

Select or Create Specification

To create specification limits in your LDB, you first need a specification (reference range table). Click edit on the desired specification or add a new one via + Create Specification.

Define Specification Limits

Select Parameter

There are two ways to add parameters:

1. Targeted Search

• Click on the dropdown menu Search Parameter.
• Select the desired parameter from the list.

2. Use Overview

• Click on Show All Parameters.
• Add parameters by clicking on the blue plus symbol to the right of the desired parameter.

• You will then automatically access the view where you can create rules for the parameter and thus define the specification limit.

Create Specification Limit for Parameter

With specification limits, you can define reference ranges for each parameter in the LDB and have deviations marked in color.

How to create a specification limit for the previously selected parameter:

• Select the parameter column to which the specification limit refers in the first dropdown menu.
• Select the operator (=, <, >, ≤, ≥, !=) in the second dropdown menu.
• Enter the specification limit in the third field. If a dropdown menu is configured for the selected parameter column, for example, you can select the specification limit directly from the dropdown menu.
• For ranges, you can combine multiple conditions. Use the fourth dropdown menu for this and select AND or OR as the connector.

Note: In the standard configuration of the LDB, you always define the valid reference range. Only values that lie outside this range are marked with the selected color.

Below you will find the most common use cases:

Maximum Value (Upper Limit)

Use case: A value must not exceed a certain maximum value.
Example: The temperature should remain below 5 °C.

• Rule: Value < 5
• Result: Values ≥ 5 °C (e.g. 8 °C) are automatically marked in the selected color.

Range (Between Two Values)

Use case: A value must lie within a defined range.
Example: The temperature should be between 3 °C and 5 °C.

• Rule: Value > 3 AND < 5
• Use the AND function (AND) with corresponding comparison operators.
• Result: Values ≤ 3 °C or ≥ 5 °C are automatically marked in color.

Outside a Range

Use case: Only values outside a certain range are valid.
Example: The temperature should be either below 3 °C or above 5 °C.

• Rule: Value < 3 OR > 5
• Use the OR function (OR) with corresponding comparison operators.
• Result: Values between 3 °C and 5 °C are automatically marked in color.

Fixed Value (Exact Match)

Use case: A text value or selection option must match exactly.
Example: For visual inspection, only clear is accepted as valid.

• Rule: Value = clear
• Use = for equality or != for inequality.
• Result: All values except clear are automatically marked in color.

Combination of Text and Numbers

Use case: Both text values and numeric values are defined as valid for a parameter.
Example: For microbial count determinations, the result can be either "nd" (not detectable) or a numerical value below 10

• Rule: = n.d. OR < 10 (< 10 OR = n.d. doesn't work)
• Use the OR function (OR) for linking
• Important: The text comparison must be in first position.
• Result: Both the text n.d. and all numerical values < 10 are considered valid. All other values are automatically marked in color.

Set Frequency

Define the frequency with which the specification limit must be met in tested samples.
Example: The specification limit must be met in every 2nd sample.

Choose Color Coding

Select the color in which values that do not meet the specification limit should be displayed (red by default). This enables quick visual detection of deviations.

Activate Report Integration

Check the checkbox show this rule in report to display the specification limits together with the measured values in reports.

Add Additional Specification Limits

After saving, you can add additional specification limits for the same parameter if needed:

• Click on the + next to the parameter
• Define additional rules using the same schema

This is useful when you need different specification limits for different situations (e.g. warning and limit values).