Aligned Elements is a Medical Device application lifecycle management (ALM) solution enabling fast development and regulatory compliance through improved Design History File management.

October 04 2014

Preliminary Hazard Analysis is a risk assessment technique performed in the early the design phases. It is a powerful method to document and assess device risks without having the full implementation completed and to highlight problematic risk areas early on.

hazard

We have previously discussed how the PHA compares with the FMEA method in Aligned Elements and how they complement each other. The templates needed are available here.

Learn more about Aligned Elements and Riskmanagement

Request a live demo and let us show you how Aligned Elements helps you with your Preliminary Hazard Analysis

September 04 2014

I say "IEC 62304 Software Safety Classification", you say "A, B, C".

If you have worked with IEC 62304, you have (probably) also faced the challenge of assigning Software Safety Classifications to the Software Items. It has to do with associating a risk level to your software items in order to assess how careful you need to be when you document, develop and test them.

Now, if you work with medical device development, it has probably dawned to you that you are already doing risk management. Lots of risk management. All sorts of risk management. Is it possible to use the existing risk assessments when doing our IEC 62304 work? Yes, I think so.

When a software designer/architect constructs the software architecture needed for IEC 62304, there are lots of approaches to choose from. The norm is explicitly ambiguous on this point. In short, it is up to you to pick an approach. It is however not uncommon for the software designer to use established modelling techniques such as UML, Object-oriented design, multi-layered design, SAAS etc. which in most cases results in number of boxes (the software items) with names like:

  • User Interface
  • Logging
  • User Management
  • Reporting
  • Data Access Layer
  • Persistence
  • Serial Communication etc.

So are we supposed to perform a risk assessment of these boxes now?

What strikes you immediately is the insight that these boxes in themselves do not "have" risk. Why? Because we have not defined the context in which they are used. Software risk emanates from how we use the software i.e. in which functional aspect we use the software items.

The guys of Certified Compliance Solution have solved this in a really neat way using what they call "The Matrix Model for Software Safety Classification". It is well summarized in the picture below.

MatrixModel

 

The CCE people have correctly identified that functional flows cut accross the software architecture.

In their model, Software Items are listed on the horizontal axis and User stories (or Epics, Use Cases, Work Flows, Specification or whatever you want to call them) are listed on the vertical axis. Now, risk assessments for User Stories is something we do every day so that part should be pretty straight-forward. Once that is completed, we can deduct a classification for each User Story based on this risk assessment (more about that later).

The Software Designer can now point out the Software Items that implements our User Story in the software. After we have done this for all User Stories, the software Safety Classification for a Software Item is simply the highest risk of its aggregated use, which is summarized in the bottom line "Overall SW Item Safety Class".

Isn't it beautiful?

Let me show you how this is implemented in Aligned Elements.

First, I introduce the Document Object type "Use Case" which will represent the user stories. Then I set up Document Object types for Software System, Software Item, Software Unit and SOUP which all have a Software Safety Class attribute being A, B or C, with the default value C.

I can then proceed to document the Use Cases and structure the Software Architecture separately.

Now, time for risk assessment. I will use the integrated Preliminary Hazard Analysis (PHA) to assess my Use Cases. When working out the risks using the PHA method, I am requested to define the possible Cause(s) for each risk. The Cause has a severity attribute and I will use this severity to calculate the Software Safety classification. If the Cause is emanating from the software, I further tag the Cause originator as "Software".

62304RA

I go back to the Software Item definition and map the values A, B and C to a Severity range in the Cause i.e. a Severity from 1-3 maps to Class A, Severity 3-5 maps to Class B etc.

To tie it all together, I trace the Use Cases to the PHA risks and (here comes the trick) Software Items to the software originated Causes.

 

62304UseCaseTrace

 

I run an Inconsistency analysis on the Software Items and get a report on how well the Software Item Safety classifications match the risk assessment, including suggestions on what the Software Safety Classification ought to be based on the associated risks.

 

62304SWItemInconsistency

 

Simple, transparent and consistent.

So we have a range benefits from this approach:

  • We perform risk assessment where it makes sense i.e. to Use Cases.
  • When we map use cases to software items via the risks, automatic checks that ensure that the maximum severity of the risks match to the software item safety class.
  • We have reused the use case risk assessment in our IEC 62304 implementation.
  • We have used traces to establish the relationships between use case, risk and software items and automatically get the required traceability for free.

Once again we have showed the benefit of integrating all Design Control Items in a single system.

The sum is truly greater than its parts.

  

July 18 2014

On July 19th, 2014, we release Aligned Elements V2.2 (2.2.7.9739) which includes the new Aligned Elements Web Client.

The Aligned Elements Web Client enables browser-based access to any Aligned Elements project from any remote location.

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 TraceExplorerConsistencyCoverageWebChart

It is the efficient way to involve and benefit from external project stakeholders such as customers, suppliers, distributed marketing teams, external testers and other remote team members in the Design History File collaboration process.

The web client permits the user to perform core activities such as creating, updating and tracing Document Objects, managing chapter hierarchies, inspecting the project content, running queries, performing free text searches etc.

The new interface is optimized for easy access to core Aligned Elements functions  and combines high performance with a modern interface to enhance the user experience.

For the Windows Client V2.2, we have added a number of new features, most notably:

  • Bookmarking favorite Document Objects
  • Inclusion of the Revision History in Document Object XML exports
  • Optionally including old revision data of Document Objects in Excel reports
  • Copy users to other projects in order to minimize User management effort

We hope that you will enjoy these improvements.

July 17 2014

Traces are the glue.

Traces are the links that tie the development documentations together. They provide basis for verifying completeness and consistency.

Traceability, the discipline of setting and managing traces, is a core activity in the medical device development process. Norms and directives such as ISO 13485, ISO 14971, IEC 62304, IEC 62366 and FDA CFR 21 QSR 820 explicitly prescribe it.

Traces in a medical device project

In essence, establishing traces between artefacts is a deceptively straigh-forward task. You just declare the trace and that's it. So why is traceability perceived as such as annoying piece of work?

The main reason is change.

As mentioned above, a trace establishes a relation between dependent artefacts (e.g. a requirement and a specification). When change occurs to one party in this relationship (the requirement), the state of the traced artefact (the specification) may become invalid.

Word documents and Excel sheets are notoriously inept at handling this kind of problem, since the artefacts are not aware of eachother.

Traces in an Excel sheet are just dead text.

On the other hand, this is why traceability software tools such as Aligned Elements are so popular. Traceability softwares tools not only allow traces to be declared, but are also able to track changes made to the traced artefacts.

A change in an artefact automatically highlights the affected traces and signalizes that they might have become invalid due to the change. In Aligned Elements, we call such a possibly invalidated relationship a "suspect trace".

The user now has possibility to inspect the implicated artefacts and update them if needed. Or simply confirm that the the change did not have any impact on traced artefacts. In Aligned Elements, an impact analysis entry is made in the audit trail as the user complets this action, in order to ensure accountability throughout the development process.

However, these gains are quickly lost if different artefact types (e.g. tests and risks) are kept in seperate systems. Managing traces across system boundraies is often only possible by resorting to manual measures. Such as Excel. And then we are back to where we started.

Keeping all traced artefacts in a single system further helps disentageling a range of more mundane problems, such as finding out:

  • If some artefacts have not been traced
  • If some artefacts trace to artefacts of the wrong type
  • If some traces simply don't make sense

Trace consistency

In Aligned Elements, we have implemented traceability support following a few simple guidelines:

  • Usability. It shall be easy to set or remove a trace, regardless of the working context. Therefore we have five different mechanisms for setting traces.
  • Accountability. All trace-related operations shall be recorded chronologically in the audit trail.
  • Transparency. Missing, illegal and suspect traces must be immediatly and automatically highlighted.
  • Completeness. End-to-end traceability must be facilitated without having to cross system boundaries.
  • Reportability. Trace reports shall be customizable and configurable to match the quality requirements and look-and-feel criteria of each customer.

Again, traces are the glue.

Managed correctly with the right ALM support, they are (besides being regulatory necessities) a real asset to your design history file management. The traces help you ensure that completeness and consistency has been achieved throughout your development documentation. We are doing our best to make sure this becomes a smooth journey.

June 20 2014

Zühlke Engineering AG in Zürich (http://www.zuehlke.com), has been
evaluating Aligned Elements during the spring and we recently had the
opportunity to speak with Mr. Claudio Schödler, project manager at Zühlke,
about the results.

"Having finished the evalation of Aligned Elements after 3 months of
careful study, we can conclude that it is a highly suitable application for
medical device development projects." Mr. Claudio Schrödler summarises.

"The tight integration of the risk management functions is a particularly
strong advantage when working in this industry.", Mr.Schödler continues.
"In comparison with other similar applications, we have noted that Aligned
Elements excels in terms of ease of use and reporting. Most teams will be
up and running in a very short time.”

"As you work with the application, it becomes apparent that the Aligned
team has focused on easing the documentation burden, and succeeds in doing so very well.”

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