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Conceptual BF Document

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Laboratory Ordering and Fulfillment

The Architecture Review Board (ArB) in conjunction with the Orders & Observations Work Group selected the Laboratory Domain to challenge the new SAIF Behavioral Framework and methodology. OO and the former Lab SIG/WG were stuck for years in balloting by a negative vote which Lab itself was unable to solve (and therefore, Lab eventually withdrew the Lab Order topic). That negative had at it's basis a negative-major comment regarding the lack of a current dynamic model and balloted artifacts to sufficiently communicate the Laboratory Ordering interoperability behaviors.

Document Status

Note that this document is in development, so pre-draft. It’s being circulated amongst a few HL7 work groups to socialize the discussion topics which lead to the foundation of the SAIF behavioral model requirements. Feel free to provide feedback; with that understanding (this is pre-draft). To find unfinished parts, search for <???> and for Discussion point: The <???> denote places where the core authoring team is adding content. Discussion point: items are so tagged to initiate places for OO, et. al. to discuss

Document Purpose

The purpose of this document is to highlight and discuss requirements for the SAIF behavioral model (aka dynamic model) as well as recommended business and technical artifacts needed to support this new model. The basis or source of business information for this document is healthcare services storyboard narratives, specifically those about lab ordering and resulting, collected from the International HL7 Standard, Canada, United Kingdom, and Australia. The intended audience for this paper is the Health Level 7 International Organization (HL7).

Overview

The HL7 Architecture Review Board is proposing that HL7 use a new framework for developing standards. The framework, called Services-Aware Interoperability Framework (SAIF), is based on principles from a few industry standards (e.g. RM-ODP, SOA) customized for the specific standards environment which is the business of HL7. This framework is defined and described by four components:

  • Enterprise Conformance and Compliance Framework (ECCF)
  • Governance Framework (GF)
  • Behavioral Framework (BF)
  • Information Framework (IF)

The Behavioral Framework includes a behavioral model which documents the ‘actions’ during the exchange of information between systems. In the current HL7 methodology, this is referred to as the dynamic model.

The key concepts in the current dynamic model are trigger events (what is the receiving system to ‘do’ with the information communicated), receiver responsibilities (what other activities does the receiving system perform in response to receiving a communication), triggering events (what happened on the sender side that caused this exchange of information), and status codes (represents the ‘state’ of objects within a communication). See Appendix B for a list of dynamic model requirements as seen through a MIF (model interchange format) viewpoint.

In SAIF, the behavioral model is the definition and description of expected behaviors the sender is requesting the receiver to perform with the included information model. Prior to SAIF, this was called the dynamic model and included trigger events and receiver responsibilities. To determine and discuss the requirements for the SAIF behavioral model, this document will start with simple use case narratives (storyboards) and progress towards more complex use cases with discussion after each narrative to elaborate behavioral model, information model, and governance model impacts unique to that narrative focusing on the behavioral aspects.

This discussion document initially frames behavioral requirements via HL7 storyboard narratives from the Laboratory domain which describe increasingly complex behavioral interoperability paradigms. The Lab domain is the most complex set of behavioral/process flows owned by the Orders and Observations Work Group and was chosen as the basis for behavioral model discussions in this document.

Following each storyboard narrative is a breakdown of the represented business process, objects for exchange, and the state or status of each object if appropriate. From these data points, requirements will be abstracted and documented.

Business Scenarios

Below follows business scenarios and processes with discussion immediately after each to highlight relevant points from that particular scenario or process.

Storyboards and Discussion

Below follows storyboards and discussion immediately after each to highlight relevant points from that particular use case or set of use cases.

Roles and Interactions

The initial use cases can be broken down into interactions between a sender and an intended receiver (who is also the fulfiller). In terms of the Behavioral Framework, these are the Commissioning Party and the Responsible Party. Based on the role and accountability / obligation we can derive a set of business services that realize the required behaviors and manage the appropriate state transitions. These services can be composed into interactions and interoperability scenarios and implemented by a variety of exchange patterns (request/response, publish/subscribe, synchronous or asynchronous messages, etc).

 LC Comment:
 Working on recasting this into the language of the Behavioral Framework. Commissioning Party, Responsible Party, Obligations, Operations, Information Exchange, Exceptions.
 I will leave comments to indicate where I am in progress, then remove them as I work through it.

The first thing is to identify the roles. So far, we have:

Role Description BF Mapping
Order Requestor (Placer in v2) Places the original request, and waits for it to be completed Commissioning Party
Request Fulfiller) Accepts the request, and then carries out the activities to fulfill what was asked Responsible Party
Fulfillment Manager Monitors the Order Requestor as it receives activities which fulfill the original request and determines when the fulfillment activities ‘complete’ the request May be the commissioning or the responsible party at different stages of the business process flow
LC Comment:
 As we work through the use cases identifying operations with related information objects, this next table should be transformed into one with headings
 Commissioning System Role || Required Interface || Responsible System Role || Responsible Agent / Service Interface || Operation
 
 The operations each then wrap the information payloads, carry out specific obligations and effect the state transitions, and may eventually define exceptions. 
 If we think this is the correct path, the next suggested step is to attempt a UML computational model based on the use cases, then revisit this table. 

The state transitions in the request and promise class are linked by exchanges between the systems that play the two roles. They can be presented in a tabular form:

Initiator Exchange Name Information Request State Before Request State After Promise State Before Promise State After
Order Requestor Request Request identity
Patient identity
Provider identity
Test list
Null Active Null Request to Fulfill
Fulfiller Accept Request identity
Patient identity
Predicted Delivery
time?
Null Promised Request to Fulfill Intent to Collect
or
Intent to Fulfill
Fulfiller Refuse Request identity
Patient identity
Reason for Refusal
Null Refused Request to Fulfill Rejected
Fulfiller Complete Request identity
Patient identity
Active Complete Request to Fulfill Complete
Fulfiller Fail Request identity
Patient identity
Reason for Failure
Active Aborted Intent to Fulfill Aborted

These interactions can be assembled into services using either request/response, publish/subscribe, or implemented using synchronous or asynchronous messages. But whatever the architecture, these are the essential information exchanges that need to occur. Missing from this table are other obligations that the order requestor and fulfiller have. Some of these obligations are shared in all the various incarnations of the lab request/report cycle, while others vary wildly. The most obvious obligations pertain to the fulfiller:

  • Carry out the work that is promised (if possible – i.e. can’t do it if the patient doesn’t turn up)
  • Ensure that either a complete or failed exchange actually happens in the end

Other obligations might be to validate that the request is valid, or to inform other systems, or to perform some further business processing. These obligations are out of scope when building an interoperability standard, as are the obligations on the placer such as ensuring that the order is one it is allowed to submit.

Additional Requirements

However, this is not all there is to lab orders. There are several key additional requirements that need to be provided for.

Order Brokers

Order Manager

The most common end state for the request cycle is that the laboratory or fulfiller claims that request has been completed. An important question is whether the placer agrees that whatever was requested has actually been performed. There are several reasons why the placer may not agree:

Clerical Error The whole point of this request cycle is that there should be no capacity for clerical error
Configuration Error The mapping between the request code and the lab system test code may be in error
Clinical Interpretation The lab applies clinical judgment when deciding what to do; there may be disagreement between the clinician and the lab in this area.

For this reason, many clinical systems that place lab requests provide functionality to check what was performed against what was requested; this is known as an “Order Manager”. It also tracks the requests so that some clinical user can be alerted in the case that requests are not progressing or completed – for instance, if the patient does not attend any lab to have their specimen(s) collected.

PEL Comment:
Order managers also typically manage what are called “Parent” or “Recurring” orders. Order manager functionality may be part of
the placer system, filler system, or an independent system. An order manager can take a parent order, explode it into occurrence
(aka. Child orders) which are then sent to the filler system. An order manager may also take a “composite order, explode it into
individual orders and forward them onto the appropriate departmental filler system. This is the idea behind our V3 Composite order.

AJK: An example of exploding a composite order, consider a composite order containing both an Rx order for warfarin and a recurring lab order for PT/INR. The order manager would explode the composite order into the drug order, which is forwarded to the pharmacy application, and the lab order, which may be exploded into a series of occurrence orders that are sent to the lab application at the appropriate time.

In order for the Order Manager to function, it must be able to track the laboratory reports and compare the list of reports received, along with their status and contents, against its own expected list. To enable the Order Manager to track the reports, all the reports that the lab sends to the placing system must identify the request(s) that the report is considered to be fulfilling. As discussed above, this may occur even after the request/promise cycle is complete.

When the order manager detects an issue, it must notify a human. There are no request or promise state transitions related to the order manager. However there is an exchange related to the order manager: the order manager may inform the laboratory that it has detected an issue as well as informing its own users through some process that is out of scope for this analysis. In order to treat this consistently, we can define an order manager object, along with a laboratory equivalent.

TrackerObj.PNG

Again, these objects do not have an explicit identity of their own that we interested in, and they do not need to directly exist in that form – all this is saying that from an external perspective, the systems behave as if these objects exist.

TrackerSM.PNG

These are very simple state transition diagrams. There are many other potential states related to the interaction of the logical trackers with humans (review, mark-off, etc), but these are not relevant to the request/promise cycle.

Putting it all together

Taking all these extra factors gives us final state transitions for request and promise that look like this:

RequestFinal.PNG

PromiseFinal.PNG

Action Items

  • Action Item update September 1, 2011
    • Patrick to look at putting all together section doesn't logically follow the SM above, due to edits. (Patrick)
  • Future Items - out of scope for Lab Order Release 1
    • future: Need to look at JK broked fulfillment section (Jean)
    • future: order broker section (Jean)
    • future: order manager (Austin)
    • future: Standing order tracking fulfillment story board
    • future: other pending order (np orders, md student orders) which require supervision
    • future: order authorization
    • future: add Austin’s public health storyboard? Namely CDC requests specimen, local lab system ‘places’ order – public health entity is the fulfiller.i
  • To do items from September 2011 WGM
    • Create conceptual datatypes for items needed by conceptual models
    • Review model interactions for consistency
    • Consider naming conventions for parts of the artifacts, and identifies
    • Add the business context text to the use cases, and to the service specifications

Appendix A - Comments, Questions, Concerns Summary

  • We realize this is early in the process, but both Austin and I (Patrick) were surprised that we didn’t see more of the ‘new’ language of behavioral framework (words like collaborations, exchanges, contracts, etc). Of course, could be this is too early and that’s the next step (or a step after).
    • LC: Behavioral framework terms coming in via the Roles and Interactions section as the models created based on the storyboards. Need to update the document as we elaborate
  • We are seeing new ‘states’ as they relate to services which break down differently than messaging (of course). But it’s difficult to tell how the various HL7 state machines map to the service states.
  • Notes/questions from modeling effort
    • Information structures - Request/Request Component. Need to deal with nested nature of requests
      • Patrick to look at entities to consider nested requests
    • Promise Management - is this really a separate service or is it managed by the fulfillment contract?
      • LC - so far, promise is not a separate service, but an information object that is managed by the fulfiller
    • Separate service contracts behind the fulfillment manager
    • Clarify collection and request lookup flows in business process model. Should lanes be separated?
    • At the conceptual level, the Fulfillment Manager role is accountable for the communicateResult operation, so it should be modeled with that service, as a push that might be implemented by a variety of message exchange patterns at the logical level (polling / push notification / etc). EA does not easily let you express this in a conceptual level interaction diagram - for now, handling this with notes on the model.
  • Notes from EA / package structure configuration
    • MnM has said they prefer XMI 2.1 as model serialization format, since it is more shareable with other tools. In Enterprise Architect, I can export a package/model to 2.1 for sharing with other tools, but I cannot save to that format when creating XMI to use with Subversion version control and HL7 GForge
    • EA svn alias used %hl7-oo-gforge%
    • Current version of EA 9.0.907
  • Other notes
    • Artifact definitions are being developed and clarified by MnM. Ongoing work here means change to the definitions is happening - we will manage those shifts by synching up with their requirements at defined points in our documentation creation, rather than continually trying to keep up