Using Precursor Schemes to Manage Workflow

• Using Precursor Schemes to Manage Workflow
  • Overview
  • Process
    • Establishing Precursor Scheme Relationships
    • Setting Precursor Scheme Relationships between Sample Schemes and between Job Schemes
    • Automatically Registering Precursor Schemes on Samples
    • Impact of Precursor Scheme Relationships between Job Schemes
      • Propagating QC Samples Registered on Precursor Schemes to also Register them in Sequel Job Schemes
    • Impact of Precursor Scheme Relationships between Sample Schemes
      • Sample Scheme Readiness
      • Sample Scheme or Sample Scheme Analyte Expiry

Overview

A precursor scheme is a scheme that must be process in the laboratory before one or more sequel schemes are processes. This typically includes analytical preparation scheme work that occur before analytical scheme work.

When considering the flow of work through the laboratory, various processes are affected by precursor scheme relationships.

Precursor scheme relationships between job schemes control the order in which QC masks on sample schemes are processed to add QC samples to a job when appending or overwriting QC samples for selected job schemes.

The state of a precursor sample scheme determines whether a sequel sample scheme is available for batching and which sequel sample schemes may be expired for analysis:

• A precursor sample scheme's Ready Date can be used as a sample search criteria when searching for samples to batch. A precursor scheme scenario could be that you do not want to include samples in the count for analysis until their preparation is at least started, or one sample scheme may have a varying preparation pathway, or different samples may have a different combination of precursor schemes and sequel schemes.

• A precursor sample scheme's Completed Date is used to determine a sequel sample scheme's Warning Date and Expiry Date and sequel sample scheme analyte's Warning Date and Expiry Date, which can be used to lock sequel sample scheme analyte's cell in a workbook session.

Process

Establishing Precursor Scheme Relationships

A precursor scheme relationship involves a precursor and sequel scheme. Precursor schemes relationships are created between two schemes using the CCSCHM—Scheme application. Refer to Maintaining Precursor Schemes for a Scheme.

When considering precursor schemes, the flow is generally sample preparation, followed by analytical preparation, followed by analytical schemes, although a sample preparation scheme may be a precursor of another sample preparation scheme, an analytical preparation scheme may be a precursor of another analytical scheme.

When establishing linked scheme relationships between master schemes, schemes can only be linked where both schemes have the same set of precursor schemes. This is due to sample portions and rack containers for linked sample schemes being the same physical sample portion that has come down the same precursor pathway.

Setting Precursor Scheme Relationships between Sample Schemes and between Job Schemes

When a scheme and one of its precursor schemes is registered on a sample, then the precursor scheme relationships between the sample schemes are inherited from the master scheme. The schemes do not have to be registered at the same time on the sample for this to occur. Refer to Adding a Group of Samples to a Job. When an org-scope scheme is registered on a lab-scope job, then the precursor scheme relationships are determined from the enabled-scope schemes.

When a template sample is used to add schemes to a sample, the precursor sample scheme relationships are inherited from the template sample instead of from the master schemes. Refer to Creating Production Jobs from Template Jobs, Adding Samples using a Template Sample to a Job and Adding Tests using a Template Sample to a Sample.

If the registration of the sample schemes cause the creation of job schemes, then the sample precursor scheme relationships are established between the job schemes.

Where more than one scheme is registered on a sample, if an existing or newly added sample scheme does not have a precursor scheme assigned, then precursor schemes are assigned where relationships exist in the master scheme, as follows. Given scheme SCH_1 has precursor schemes SCH_A_PRE_1 and SCH_A_PRE_2. There are three initial situations to consider:

1. Sample1 has scheme SCH_A registered with no precursor set for Sample1 SCH_A.

   Then Sample1 is updated (either in a single or multi sample update) and schemes SCH_A_PREP1 and SCH_A_PREP2 added, and the update submitted.

   SCH_A_PREP1 is set as Sample1 SCH_A’s precursor since it is earlier than SCH_A_PREP2 alphanumerically.

2. Sample1 has schemes SCH_A_PREP1 and SCH_A_PREP2 registered.

   Then Sample1 is updated (either in a single or multi sample update) and scheme SCH_A is added, and the update submitted.

   SCH_A_PREP1 is set as Sample1 SCH_A’s precursor since it is earlier than SCH_A_PREP2 alphanumerically. (Same rule as above.)

3. Sample1 has schemes SCH_A and SCH_A_PREP1 registered, but the precursor was removed from Sample1 SCH_A.

   Then Sample1 is updated (either single or multi sample update) and scheme SCH_A_PREP2 is added, and the update submitted.

   SCH_A_PREP1 is set as Sample1 SCH_A's precursor since the existing SCH_A_PREP1 is ignored when setting the relationship, even though it has an earlier alphanumeric code compared to SCH_A_PREP2.

Precursor schemes can exist as a network. Where more than one sample scheme is a precursor of a sequel sample scheme, then the sequel sample scheme's Precursor Scheme Code is set to the first precursor sample scheme, based on alphanumerical order, after which it can be updated to link to a different precursor sample scheme. For example:

• Where a sample has schemes B, A and C registered in that sequence, and precursor scheme relationships on the master scheme indicate that both A and B are a precursor scheme of C, then the precursor of the sample scheme C is sample scheme A as it precedes B in alphanumeric order. This can be updated on the sample, to override the automatic assignment to a different precursor scheme, if required.

Refer to Maintaining Job Tests and Maintaining Sample Tests to maintain precursor scheme relationships between job scheme and sample schemes, respectively.

Automatically Registering Precursor Schemes on Samples

When a master scheme is registered on a sample, if the scheme has one or more precursor schemes with Automatically Profile selected, then the precursor schemes are registered automatically on the sample and placed before the scheme that was manually registered. This is typically used to automatically register an analytical preparation scheme when an analytical scheme is registered on a sample.

Note: Automatic registration only proceeds if the precursor scheme is either a laboratory-scope scheme or an organisation-scope scheme that is enabled for laboratory use.

Impact of Precursor Scheme Relationships between Job Schemes

Propagating QC Samples Registered on Precursor Schemes to also Register them in Sequel Job Schemes

A QC sample created early in the flow of laboratory work often has to be included in a sequel process. That is, when a QC sample is created in a precursor job scheme, it can be propagated into a sequel job scheme to create a sequel sample scheme.

QC samples are propagated into sequel job schemes in two ways:

• When an update/overwrite QC process is run on a job scheme, if the QC mask member used to create the QC sample for a given job scheme has Propagate selected, then the sample is also registered for any linked or sequel job scheme. Refer to Maintaining QC Masks and Processing a Job Scheme to Add QC Samples by Applying QC Masks.

  Note: When an update/overwrite QC process is run on a job scheme, job schemes that are linked are always given the same QC samples and rack layout.

• When a QC sample modification process is used to add a QC sample to a job scheme, then the sample is also registered for any linked or sequel job scheme. Refer to Maintaining Batch Samples.

When a QC sample is propagated into a sequel job scheme:

• If the QC sample has a Primary Analytical Type of Duplicate, Replicate or Spike, then the original unknown sample to which it pertains must be registered for that sequel scheme for the QC sample to be registered for the sequel job scheme.

• If the QC sample has a Primary Analytical Type of Blank or Standard, then it is registered for the sequel scheme.

• QC samples are registered into sequel job schemes in the same relative Registration Sequence on the sample schemes, as they were added into the precursor job scheme.

Impact of Precursor Scheme Relationships between Sample Schemes

Sample Scheme Readiness

Precursor scheme relationships are useful where a specific sequence of analysis is required.

When returning sample counts for schemes and analytes for Batching Samples for Analysis, then sample counts can be based upon whether precursor sample scheme's Workflow Status is Started or Completed, or whether the precursor sample scheme's Ready Date is set, which is based on the precursor sample scheme's Waiting Time.

When searching for samples for Batching Samples for Analysis, then the samples can be filtered similarly. Refer to Using Waiting Times when Batching.

Sample Scheme or Sample Scheme Analyte Expiry

Holding times are used to establish the time period for the validity of a sample for analysis, before the sample has deteriorated enough to impact upon the test result and warning times are used to indicate samples coming up to expiry. Warning and expiry date-times of sample schemes and sample scheme analytes are calculated based upon holding times of sequel schemes. When searching for samples when Batching Samples for Analysis, then samples returned from a search can be ordered based on the sample scheme and precursor sample scheme expiry date. Refer to Using Sample Expiry when Batching.