We argue the need to demonstrate the value of preservation services to institutions, the public and funders, because it matters conceptually and needs to be supported and validated. To address this imperative, improved and focussed data capture and its use by collection managers is advocated as the necessary first step towards the development of an evidence-based culture for preservation services and synoptic decision making, where evidence enables us to optimise the outcome of planning.To do so, we need tools that enable us to evaluate diverse preservation scenarios. We demonstrate the potential of emerging cross-disciplinary tools and protocols developed in the recent years such as attitude surveys, computational modelling and demographic modelling. These offer evidence that informs prospective preservation planning, and, importantly, provides a credible evidence base for advocacy. These possibilities are discussed within the wider context of well-established preservation planning protocols that have shaped collection management for three decades, broadly characterised as retrospective.1. There is no single correct solution as the end goal is often not well defined (e.g. the longterm horizon in preservation is often defined as "forever" or "as long as possible") 2. The problem is frequently redefined and end goals are adjusted to fit the available means 3. Decisions are designed to avoid negative impacts rather than to achieve desirable ones 4. The decision (and policy) process is ongoing and never ends.There are positive and less positive aspects of incremental decision making. It could be seen as realistic and pragmatic, as it rarely moves away from accepted practice, however, in doing so, it rarely considers radical shifts in policy if conditions change markedly. Do the precarious economic and social situation in many countries and the impending climate change require of us to consider more radical approaches to decision making? Accepting the principles of economic efficiency, synoptic planning attempts to optimise returns. It is based on the following steps: (i) Problem definition, (ii) Goal definition, (iii) Options appraisal, (iv) Choice of the optimal solution, (iv) Outcome monitoring. The most important criticism of synoptic