Using Waiting Times

Overview

Waiting times are the time periods applied to precursor schemes to implement a forced delay before the next scheme to be analysed (the sequel scheme) is started. This technique is used when the test might require a process that takes a period of time, such as curing, settling and other sample preparation techniques.

After a defined waiting period has passed, a sample scheme's ready date indicates when the analysis can resume fora sequel scheme, or the associated sample portion can be released for preparation. When batching samples for analysis, samples can be located based upon the readiness of the precursor sample scheme.

This allows an operator to return only samples that are ready for batching, that is, where their precursor sample scheme is deemed ready for the associated sample portion to be released for preparation or analysis by the sequel sample scheme being batched.

Process

How are Ready Dates Calculated for a Sample Scheme?

A sample scheme's Ready Date is determined as the sample scheme's Started Date plus the scheme version's Waiting Time. Typically, a sample scheme's Ready Date will be later than the sample scheme's Completed Date, which allows operators to prepare and leave samples for a specified time period before the next scheme (the sequel scheme) is applied.

If any parameters are missing for the determination, for example, the scheme version's Waiting Time or the sample scheme's Started Date), then the sample scheme's Ready Date is left empty.

Note: The calculation of a sample scheme's Ready Date is not pushed out later by working days, weekends and holidays.

Establishing Waiting Times

A scheme version's Waiting Time is configured using the CCSCHM—Scheme application so that a sequel sample scheme cannot be located for laboratory batching until an amount of time has elapsed since the precursor sample scheme is started.

Waiting times for scheme versions are specified and maintained using the CCSCHM—Scheme application. Refer to Maintaining Versions of a Scheme.

Waiting times are only defined in the master scheme versions, and are not inherited by sample schemes or job schemes.

Refer to the Effect of Scheme Scope upon Waiting Times on Analysis.

When are Ready Dates Updated on a Sample Scheme?

A sample scheme's Ready Date is updated in real time, not via a system batch job, whenever any of the inputs change, so therefore at the following points:

A sample scheme's Started Date is updated by:
- Applying Sample Gridding or Entering Results into Workbook Cells to set cells to LNR, IS, NA or NR, which sets the sample scheme analyte's Workflow Status to Listed Not Received, Insufficient Sample, Not Analysed or No Result and stamps the Started Date, such that, the subsequent Workflow Status Cascade moves the sample scheme's Workflow Status on from Not Started and Started Date is set.
- Applying Sample Gridding or Entering Results into Workbook Cells to clear LNR, IS, NA or NR from cells, which sets the sample scheme analyte's Workflow Status back to Not Started and clears the Started Date, such that, the subsequent Workflow Status Cascade updates the sample scheme's Workflow Status and Started Date accordingly.
- Entering Results into Workbook Cells in final results mode, in which entering a value into a cell sets the sample scheme analyte's Workflow Status to Analysed or Check and stamps the Started Date, such that, the subsequent Workflow Status Cascade updates the sample scheme's Workflow Status and stamps or clears Started Date, and deleting a value from a cell sets the sample scheme analyte's Workflow Status to Not Started and clears the Started Date, such that, the subsquent Workflow Status Cascade updates the sample scheme's Workflow Status and Started Date.
- Completing Preparation and Miscellaneous Job Schemes, such that, the subsequent Workflow Status Cascade moves the sample scheme's Workflow Status to Not Started, Started or Completed and clears or stamps the Started Date, respectively.
- Adding a Group of Samples to a Job or Maintaining Sample Portions to update a sample portion's Location Code and Sample Handling Code which sets potentially updates a sample preparation sample scheme's Workflow Status and Started Date, accordingly.

A laboratory batch job is de-linked by:
- De-linking samples from a batch job when Maintaining Batch Samples, such that, the batch job contains schemes with precursor scheme relationships between them.

How are Waiting Times Used?

Where a sample scheme has a precursor sample scheme, when returning sample counts for schemes or analytes for Batching Samples for Analysis, then the sample count can be filtered to exclude sample schemes or sample scheme analytes where the precursor sample scheme's Ready Date is not set or is before or at the current system date-time.

This filter can also be applied when searching for samples for Batching Samples for Analysis, then the samples that are found for the selected schemes or scheme analytes are displayed and show whether each sample Is Available for Batching. This check box is selected where the sample scheme or sample scheme analyte:

Does not have a precursor sample scheme, or
The Precursor Status search criteria is selected as Started and the precursor sample scheme's Started Date is set, and/or
The Precursor Status search criteria is selected as Completed and the precursor sample scheme's Completed Date is set, and/or
The Precursor Status search criteria is selected as Ready and the precursor sample scheme's Ready Date is earlier than the current system date-time.

This allows an operator to return all samples for the batching criteria, but to then only batch those that are started, completed or ready, although, for example, an Export to Report grid flow option could be used to generate a report that contains all samples, ready or not.

The USE_IS_AVAILABLE_FOR_BATCHING application preference controls whether a laboratory batch job or subcontract batch job proceeds when any of the selected samples have Is Available for Batching selected or cleared.