Alchemy Playbooks — The Value Flow Sankey ™

AI Business Cases,
made simple — and made
impossible to argue with.

29% of organisations have seen a material return from generative AI. 75% of leaders admit their AI strategy is more about signalling than substance. The Value Flow Sankey ™ is a single-page model that aligns every pound of AI investment to the benefit it delivers — so your board sees the case, challenges it, and can't easily take it apart.

Explore the Model Work with David →
29%
of organisations have seen
material ROI from generative AI
Deloitte, State of AI 2026
75%
of leaders admit their AI strategy
is signalling, not substance
WRITER, 2026
$40m
additional margin contribution,
year one — whilst still building
David Viney, case study
1–2%
of a wall of benefits is all
your stakeholders need to believe
Viney (2026) — The Wall of Benefits
What It Is

One page. Every pound.
Aligned to a benefit.

Money — like energy — can be neither created nor destroyed. Sankey diagrams are a data visualisation technique that shows the major flows within a system, and how a property (in this case, money) changes state over time. The states being connected are called nodes; the connections are called links.

The Value Flow Sankey ™ is a modern descendant of the Benefit Dependency Network (BDN), originally developed at Cranfield University — a model that traces how investments generate value, from drivers for change through to delivered benefits. Unlike the old BDN, the Sankey starts with benefits on the left — because most people in the West read left-to-right, and because the artefact should say "this programme is benefits-led" before a single word is spoken.

In the middle sit the costs — split by Capex and Opex, grouped into build components. On the right, these regroup into the recognisable products being shipped. At a glance, you can see the expected return — the gap between the level of benefits and the level of costs — over a five-year horizon.

The Value Flow Sankey: a diagram showing flows from benefits, through costs and components, to delivered products
The Value Flow Sankey ™ Benefits → Costs & Components → Products — one page, every pound aligned
Left — Benefits
Benefits-Led, By Design

The model starts with benefits because the programme is benefits-led — and the artefact should say so before anyone reads a word. This is the reverse of the old BDN, and it's a deliberate signal to every stakeholder who looks at it.

Middle — Costs & Components
Capex, Opex, Build Components

Costs sit in the middle, split by Capex and Opex and grouped into the build components that deliver them. This is where the investment case lives — and where the gap between cost and benefit becomes the visible, defensible ROI.

Right — Products
Regrouped Into Recognisable Products

On the right, build components regroup into the products being shipped — the things the organisation recognises and can track. Every individual can see a direct line of sight from their work to the benefit it delivers.

How I Use It

From the boardroom floor:
the Jenga Tower test.

Step 01
Remake the investment case, in the room

I once led the build-out of an end-to-end, AI-powered Operating System in one of the world's largest and most complex businesses — over 300 individual agencies, each defending their own budget and tools. A financial challenge was on the table, and the programme was a legitimate target. The first move was to go directly to the senior Finance leaders and remake the entire investment case afresh, in front of them.

Step 02
Show where non-joined-up technology cost you bids

We highlighted the recent must-win bids we had lost on the grounds of non-joined-up technology — making the cost of the status quo visible and specific, not abstract.

Step 03
The "Billy Goats Gruff" gambit

We showed every agency leader how they personally could save money by eliminating duplicative spend — turning sceptical stakeholders into advocates for the platform that would let them stop paying for the same thing six times over.

Step 04 — The Decisive Move
Align the entire budget to benefits — and let it become a Jenga Tower

The smartest move: representing the entire investment budget fully aligned to benefits, some already achieved. When stakeholders challenge the case, the Sankey becomes a sophisticated Jenga Tower. Want to remove £X of cost? Tell me which £Y benefit you don't want — I know exactly which brick to pull. Pull too many, and the whole proposition visibly falls.

"$40m of additional margin contribution in year one, whilst still building the platform! And since, 12% more new business, 28% higher revenue, and done so at a 60% lower cost-per-acquisition."
David Viney — The Value Flow Sankey (2026)
300+
individual agencies, each defending their own budget, tools, and IT team
12%
more new business after the platform-based investment case landed
28%
higher revenue, at a 60% lower cost-per-acquisition
2005 → 2026
from the Benefit Dependency Network to the Value Flow Sankey — twenty years of evolution
The Wall of Benefits

You only need stakeholders
to believe 1–2% of the wall.

The basic problem with an AI case is as old as the hills: the main benefits will be indirect rather than direct — minutes saved here, friction removed there — not a single line item a CFO can trace to the bottom line. The answer isn't to find one big number. It's to build a wall so long and so provable that even a doubting Thomas can't dismiss all of it.

01
Start With a Pilot

A low-cost test of the basic tools, with a representative sample of your workforce. This is where the wall of benefits begins to take shape — small, specific, and grounded in real usage rather than vendor projections.

02
Time Survey

Get each person in the pilot to estimate how much time they saved across a range of different tasks, from using the technology. Itemise — and ideally there should be hundreds of individual tasks, not a handful of headline ones.

03
Average Cost of Labour

Get reliable data on your average salary costs across different parts of the workforce and different locations. This converts time saved into a defensible monetary figure — the bridge between "minutes" and "money" that sceptical finance leaders need.

04
Extrapolate Results

Multiply the salary bill by the time savings from the survey, task by task. It would be a brave stakeholder who dismisses 100% of hundreds of individually-evidenced benefits — and believing only 99% of them is usually enough for the case to fly.

05
Evidence Benefit Achievement

A benefit tracking worksheet lists the entire wall of benefits, with columns for who owns each benefit, when it will be delivered, and how it will be evidenced. The single most important thing is a filing system of sign-off from accountable benefit holders — file notes, emails, management accounts. Benefits always get challenged, sometimes by the person who first said they were achieved. Diligently curated evidence is more than half the battle, because most organisations don't bother at all.

How I Work

From benefits wall to
delivered, evidenced ROI.

01 · Build
Build Your Value Flow Sankey ™

Working with your leadership team to map benefits, costs, and components into a single-page model — the artefact that anchors the business case and every conversation that follows it.

02 · Pilot
Run the Wall of Benefits Pilot

A structured pilot with a representative sample of your workforce — time survey, cost-of-labour data, and extrapolation — to build the evidenced wall of benefits behind the model.

03 · Defend
Board Challenge & Investment Case

I work alongside you in the room — presenting the model to senior Finance and the board, and stress-testing it so it survives the Jenga Tower test before anyone else gets to try.

04 · Track
Benefit Tracking & Evidence

Setting up the benefit tracking worksheet and sign-off process — so achievement is evidenced as it happens, not reconstructed under challenge eighteen months later.

David Viney, Fractional CIO and AI Transformation Director

David Viney is a Fractional CIO and AI Transformation Director with over 25 years' experience leading enterprise technology and transformation programmes at the BBC, Arup, BSI, Heathrow, and WPP — where he built WPP Open, a £250m agentic AI platform.

He developed the Value Flow Sankey ™ from the Benefit Dependency Network he worked on with Cranfield University in the early 2000s — evolving a twenty-year-old model for a world of agile, cloud, and AI-driven delivery. The original investment case using this model delivered $40m of additional margin contribution in its first year alone.

He holds ACA (ICAEW) and CITP (BCS) qualifications and has served as a board trustee in the human rights and international development sectors for over a decade.

ACA — ICAEW Chartered Accountant
CITP — BCS Chartered IT Professional
Built WPP Open — a £250m agentic AI platform
Author, The Intranet Portal Guide (2005)
Benefit Dependency Network — Cranfield University
Find Out More

There is no new thing
under the sun.

The basic problem with an AI business case is as old as the hills — and so is the solution. Align every pound to a benefit. Build the wall. Evidence it as you go. If you'd like to talk through where your organisation stands, and what you need to make that all-important business case, I'm happy to have that conversation.

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