It is a familiar story. Your organisation has an expert in some scientific analysis, e.g. CFD with OpenFOAM. They deliver critical results to problems no one else can solve. They have worked there as long as you can remember. Then one day they announce they are leaving and years of experience and know-how — your organisation’s intellectual property — soon walks out of the door.

“That Person Left” Syndrome

Someone else then takes over the work, following a brief, insufficient handover — at best. Inevitably they find themselves building the CFD capability from scratch. In the meantime, problems are not being solved because “that person left”. The time and cost to rebuild the capability is considerable. With better management, the situation could have been avoided.

“That-person-left syndrome”, as we call it, is a failure in maintenance of an analysis capability within an organisation. Causes include lack of data management, records of workflows, sharing of information, upgrading of software and standardisation. Time is spent only getting a result today, rather than building a long-term capability of repeatable simulations that run on demand.


At CFD Direct, we understand maintenance. We have written on the subject as part of sustainable of development of OpenFOAM and talked about it at the OpenFOAM Open Day in 2018, (summarised in “OpenFOAM Sustainability 2018”). Good maintenance requires the following.

  • Continuous process: Do small amounts of maintenance frequently, rather than as one large dedicated “upgrade” effort.
  • Commitment: Recognise that maintenance is critical, not optional; reward staff for good maintenance.
  • Time: Allocate time for maintenance as part of routine daily activities.

OpenFOAM Maintenance

OpenFOAM-dev is the OpenFOAM development version, packaged regularly for easy installation. As an effective release version it must be “always-releasable” quality. Its existence drives good maintenance of OpenFOAM: the OpenFOAM-dev repository evidently tells a story of a continuous process, with commitment and an allocation of time. The benefits of good maintenance were clear soon after its release as we documented in Issues with OpenFOAM, part 1, 2 and 3.

OpenFOAM is sustainable through a strong policy on maintenance which minimise the risk and limit the impact of that-person-left syndrome. Greater authority is granted to contributors who demonstrate commitment to OpenFOAM, and its maintenance. Most potential contributors will move on to something else; if their code is dumped unchecked into OpenFOAM-dev, users will soon find themselves struggling to work with unsupported, buggy functionality.

Funding OpenFOAM Maintenance

CFD Direct has a committed core team which manages and integrates contributions to OpenFOAM. But the work requires funding.  That is why we initiated campaigns at the OpenFOAM Foundation for funding OpenFOAM in 2020 (and in 2019 and 2018) through Maintenance Plans. If you are familiar with that-person-left syndrome, you should see the need to fund OpenFOAM maintenance. Tell your organisation to buy a Maintenance Plan today.

OpenFOAM Development, Support and Training

Some organisations invest in private, internal developments of OpenFOAM — as they are permitted to do because OpenFOAM is open source. They often fall victim to that-person-left syndrome and can no longer maintain the internal developments. CFD Direct is then asked to move old internal developments into the official release. We can do this, but it usually requires us to start from scratch. In hindsight, it would have been more cost-effective to contract OpenFOAM Development from CFD Direct from the beginning.

We help our customers to build a maintainable CFD capability with OpenFOAM. Our OpenFOAM Training teaches tools for more productive CFD with greater automation of routine tasks. With our OpenFOAM Support, we encourage good management of CFD cases which are upgraded and improved with each release of OpenFOAM.

OpenFOAM in the Cloud

CFD Direct From the Cloud (CFDDFC®) is our Marketplace Product on Amazon Web Services (AWS), providing a complete platform providing OpenFOAM running on Ubuntu Linux. You can launch the system in minutes, then configure it to run simulations, and capture the customised system within an Amazon Machine Image (AMI). We maintain AMIs for some customers which provide a fully automated CFD solution on demand. One customer, Big Ass Fans, runs hundreds of automated simulations per week from a custom analysis tool as described at AWS re:Invent 2019.

Maintaining a CFD Capability