Modelling the Future Costs of Storing Print and Digital Collections

Dr Darryl MeadActing National Librarian,

National Library of Scotland

Murat GuvenHead of Resources, National Library of

Scotland

Team Roles• Darryl Mead – Acting National Librarian

Strategic planning

Guidance on shape of future budgets

Role is to commission research and then put the results to work

• Murat Guven – Head of ResourcesResponsible for delivering the empty shelf space and

provding the digital storage

Likes to model with complex spreadsheets

Storing the print collections

Print Preservation Strategy• Create and maintain an effective print

preservation environment for all collections NLS expects to hold and provide access to on a long-term basis

• Accommodate all growth of collections while maintaining a 5-year buffer of free shelf space

• We will preserve paper-based assets owned by third parties where they are on loan to us, in the same conditions as we would our own collections

Property Asset Management Plan

• Plan setting out details of all buildings and mapping all shelves, their locations and sizes

• Calculates Current print storage capacity

Predicted growth

Options for adding to capacity

Property Asset Management Plan

• ChallengeCan the Library can avoid the need for another

large storage building?

• ToolsSqueeze more books into existing space

Decide how aggressively to pursue the transition to digital rather than print content

Model the costs to see which looks cheaper

Causewayside, Edinburgh

Squeezing more print in Causewayside

• Built as a pure book store, high floor loadings

• Accommodates 100 staff

• Books shelved loosely when initally stored

• Space rationalisation programme

• Move staff to another, cheaper site

• Replace roof and outer walls to make watertight plus add a whole floor of compact book storage

Storing the digital collections

Digital Preservation Strategy• Create and maintain an effective digital

preservation environment for all collections NLS expects to hold and provide access to

• Rely on the digital preservation processes of the British Library to secure the non-print legal deposit material held within the Digital Library System

• We will not preserve digital assets where they were created by third parties and we are renting or otherwise making them accessible

Storing all collections

The National Library of Scotland

Storage Model

The NLS Storage Model

• This is a work in progress

• Larger libraries and archives all deal with similar issues

• Each one is unique, but there is a lot in common

• The model is open and can easily be adapted

What sort of a Model is it?

• Microsoft Excel 2010 spreadsheet

• Top page with:Simple data input setup using sliders

Graphical output over 30 year period

• Supporting data tables:Don’t use these tables unless you want to change

the mathematical basis of the model

The math behind the Model• Normal distributions are often used in the

natural and social sciences for real-valued random variables whose distributions are not known

• Physical quantities that are expected to be the sum of many independent processes often have a distribution very close to normal

• We chose normal distributions as the basis of calculating transitions from one state to another

https://en.wikipedia.org/wiki/Normal_distribution

Normal Distributions

https://en.wikipedia.org/wiki/Normal_distribution

Cumulative Distributions

https://en.wikipedia.org/wiki/Normal_distribution

Key variables

• Rate of decline(?) in the rate of additions to collection of print – currently 2,700 metres per year and about 260,000 items

• Rate of growth of digital collections we host and must store – current NLS capacity of on-line Tier 1 storage = 380 TB

• We assume that the Library or partners will always be responsible for our data

Print storage assumptions?

• Legal deposit is flat for UK, with hints of decline

• We have some say in speed of transition to digital

• Purchasing = 6% of intake, so has little impact

• Very large future donations are unknown, but could be added to the model in same way as space-saving projects

Digital storage assumptions?

• The amount of digital intake will rise rapidly and in some way exponentially

• The cost of storage per terabyte will fall in future; in discrete steps. Possible disruptive technologies?

• Total cost of digital storage will rise or fall depending on the strength of the relationship between rising data volumes and falling storage costs

• Digital preservation will require mirroring

• A mix of online, near-line and off-line systems

Economic assumptions?• The cost of storage per terabyte will decline over time

• The cost of creating physical storage will be relatively flat

• The cost of maintaining physical storage has many variables, but most unit costs are stable to declining

• Carbon Management Plan reduces on-going costs

• Move from BS5454 to PAS198 storage environment

Included in the Model…

• Cost of Storage declining over time:(£624/TB/per year to £122/TB/per year)

• Costs of replacing storage as it wears out

• Digital overheads increasing

• Digital born intake rising at a linear rate

Not yet included…• Cost of digitisation and cataloguing

• Cost of storing material digitised in-house

• Running costs

• Inflation/deflation

• Back-ups and disaster recovery

Not yet included…

• Scottish Screen Archive requirements

• Communications costs

• Access infrastructure

• Costs of databases, caches, queries, resource discovery tools

Model’s Top Layer

Data control sliders

Print to Digital Transition Rate

Cost parameters - digitising collections

Cost model of digitising collections

Print to digital switchover?

High speed with major change:6.4 year transition with 30% remaining as print

Medium speed with major change:10 year transition with 20% remaining as print

Slow speed with modest change:15 year transition with 55% remaining as print

Digital storage capacity profiles

Cumulative print storage costs

Cumulative storage costs of digitising

Cumulative storage costs of born digital

Cumulative costs of storage

+

=+

Cumulative storage costs

What are our conclusions?

Shelf space depletion without active space rationalisation

Inactivity = Disaster

• At 2,700 linear metres of growth per year, and keeping to a 5-year buffer…

• If we do nothing and the rate of print growth remains unchanged, we will run out of shelf space in 2016

• We will need to start build a major storage building now

• We will fail on our access mission

Shelf space depletion with active space rationalisation

Active management = Success

• If we utilise all existing space and take all other steps we can take in 2,700 metres per year and stretch this to 2027

• If print falls to only 1,000 linear metres per year in 10 years time, we will not run out of space for 50 years

• We can deliver our mission to increase access and raise our impact

Where to find our Model

Our model can be found at:

• www.nls.uk/storage-costs-model

For technical enquiries:

• Murat Guven, Head of Resources, National library of Scotland

• m.guven@nls.uk

Questions?