Updating my requirements

Last week I published my digital preservation Christmas wishlist. A bit tongue in cheek really but I saw it as my homework in advance of the latest Digital Preservation Coalition (DPC) day on Friday which was specifically about articulating requirements for digital preservation systems.

This turned out to be a very timely and incredibly useful event. Along with many other digital preservation practitioners I am currently thinking about what I really need a digital preservation system to do and which  systems and software might be able to help.

Angela Dappert from the DPC started off the day with a very useful summary of requirements gathering methodology. I have since returned to my list and tidied it up a bit to get my requirements in line with her SMART framework – specific, measurable, attainable, relevant and time-bound. I also realised that by focusing on the framework of the OAIS model I have omitted some of the ‘non-functional’ requirements that are essential to having a working system – requirements related to the quality of a service, its reliability and performance for example.

As Carl Wilson of the Open Planets Foundation (OPF) mentioned, it can be quite hard to create sensible measurable requirements for digital preservation when we are talking about time frames which are so far in the future. How do we measure the fact that a particular digital object will still be readable in 50 years time? In digital preservation we regularly use phrases such as ‘always’, ‘forever’ and ‘in perpetuity’. Use of these terms in a requirements document inevitably leads us to requirements that can not be tested and this can be problematic.

I was interested to hear Carl describing requirements as being primarily about communication - communication with your colleagues and communication with the software vendors or developers. This idea tallies well with the thoughts I voiced last week. One of my main drivers for getting the requirements down in writing was to communicate my ideas with colleagues and stakeholders.

The Service Providers Forum at the end of the morning with representatives from Ex Libris, Tessella, Arkivum, Archivematica, Keep Solutions and the OPF was incredibly useful. Just hearing a little bit about each of the products and services on offer and some of the history behind their creation was interesting. There was lots of talk about community and the benefits of adopting a solution that other people are also using. Individual digital preservation tools have communities that grow around them and feed into their development. Ed Fay (soon to be of the OPF) made an important point that the wider digital preservation community is as important as the digital preservation solution that you adopt. Digital preservation is still not a solved problem. The community is where standards and best practice come from and these are still evolving outside of the arena of digital preservation vendors and service providers.

Following on from this discussion about community there was further talk about how useful it is for organisations to share their requirements. Is one organisation's needs going to differ wildly from another's? There are likely to be a core set of digital preservation requirements that are going to be relevant for most organisations. 

Also discussed was how we best compare the range of digital preservation software and solutions that are available. This can be hard to do when each vendor markets themselves or describes their product in a different way. Having a grid from which we can compare products against a base line of requirements would be incredibly useful. Something like the excellent tool grid provided by POWRR with a higher level of detail in the criteria used would be good.

I am not surprised that after spending a day learning about requirements gathering I now feel the need to go back and review my previous list. I was comforted by the fact that Maite Braud from Tessella stated that “requirements are never right first time round” and Susan Corrigall from the National Records of Scotland informed us that requirements gathering exercises can take months and will often go through many iterations before they are complete. Going back to the drawing board is not such a bad thing.

Jenny Mitcham, Digital Archivist


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