Why Most S&OP Processes Fail — And What a Real Transformation Looks Like From the Inside

The Real Reason S&OP Fails

I have seen S&OP fail in two directions. The first is the process that never properly started — the monthly meeting where demand and supply are reviewed side by side, a forecast is updated in a spreadsheet, and the output is a summary email that nobody acts on. The second is the process that started well and then regressed — the organisation discovered that holding people accountable for a shared number is politically uncomfortable, and gradually the meetings became presentations again.

Both failures share the same root cause: the process was designed to inform rather than to decide. When S&OP has no defined decision authority, no outputs that are binding on the people in the room, and no consequences for departing from the agreed plan, it functions as an expensive coordination exercise that produces the illusion of alignment without the substance.

The Architecture That Works

The process I designed and ran at ANDS Dubai was built around the opposite principle: every stage in the 4-week cycle has a defined output, a single decision owner, and a constraint that must be resolved before the next stage can proceed.

The critical structural feature is the separation between demand review (what do customers want?) and supply review (what can operations deliver?). These are different conversations, run by different people, operating on different constraints. When you collapse them into a single meeting, the supply constraints dominate — because they are concrete and present, while the demand signal is probabilistic and future — and you systematically underplan.

Why Finance Integration Is Non-Negotiable

The most common version of S&OP I encounter excludes Finance from meaningful participation. Finance attends the executive review, reviews the numbers, and flags variances to budget. That is not integration. Integration means that the financial plan and the demand plan are reconciled at the Pre-S&OP stage, before the executive meeting, so that the executive team is making decisions about trade-offs — not reviewing a gap they cannot close.

When Finance is genuinely integrated, S&OP stops being a supply chain process and becomes the operating system of the business. Revenue, cost, and capital are all visible in the same room at the same moment. The CFO stops receiving surprises; the supply chain stops being treated as a cost centre; and the CEO has a single authoritative picture of what the business will do over the next 12 months.

The 18-Month Transformation at ANDS Dubai

The transformation I ran at ANDS took 18 months. The first three were the hardest — not because the process design was difficult, but because the cultural change required was significant. I was asking commercial teams to give up their private forecasts, commit to a shared number, and accept accountability for a planning process that would make their assumptions visible and auditable.

What made the difference was not the process design itself. It was three decisions made early:

1. The forecast became a documented assumption, not a number. Every demand plan came with an assumption log — what commercial intelligence was included, who provided it, what the confidence level was. When the forecast was wrong, we reviewed the assumptions, not just the variance. This changed the accountability conversation from blame to learning.
2. The supply review became a constraint communication, not a capability report. The supply function stopped presenting what they could do in aggregate and started presenting what they could not do, at SKU level, with lead time implications attached. This made the demand-supply gap visible in operational terms rather than percentage terms.
3. The executive review became a trade-off meeting, not a review meeting. Every executive S&OP had two or three pre-identified decisions — specific trade-offs between service level, inventory investment, and cost — that required a call from someone with P&L authority. The decisions were logged, tracked against outcomes, and reviewed quarterly.

By month 18, OTIF had improved from 78% to 96.1%. Inventory days outstanding had reduced by 28%. Emergency air freight had dropped by 30%. But the number I track most closely is the one that is hardest to measure: the proportion of decisions that were made in the S&OP forum rather than outside it. That number went from roughly 20% to over 80%. That is what transformation actually looks like.