100 day plan: cost savings that stick

Why the 100 day window matters

In the first 100 days, expectations are unfixed. Suppliers expect a review. Managers expect scrutiny. The board expects action. Once that window closes, every cost conversation gets framed as a cut rather than a reset, and the political cost of change rises sharply. Accelerating synergy capture by just three months brings forward roughly 25% of first-year savings, ^{[1, 2]} which is exactly why the sequencing below matters more than the size of the eventual prize.

Weeks 1-4: baseline and prize sizing

The first four weeks are diagnostic, not delivery. The goal is a defensible view of where cost sits, where it leaks, and what is genuinely addressable in year one versus a multi-year programme. Procurement often accounts for more than 20% of total transformation impact, with 15-30% savings available over two years, ^{[1, 2]} so this is where the baseline effort is best concentrated.

• Full spend cube: vendor, category, cost centre, GL
• Top 20 supplier contracts pulled and reviewed
• Headline benchmarks on the top 10 categories
• Sized savings prize with a confidence range, not a single number

Weeks 5-8: quick wins and mobilisation

By week eight the plan should have visible momentum. Quick wins fund credibility for the harder work in months four to twelve.

• Renegotiate the 5-10 contracts with the clearest overpayment
• Consolidate obvious duplicate suppliers
• Freeze non-essential discretionary spend categories
• Stand up a lightweight savings tracker with finance sign-off

Weeks 9-13: lock in the run-rate

The last month is about converting activity into P&L. That means finance-validated run-rate savings, updated forecasts, and a clear owner for every workstream that runs past day 100.

• Finance-validated savings tracked to the ledger, not the spreadsheet
• Policy changes (approvals, PO thresholds, preferred suppliers) documented
• Named owner and cadence for each ongoing workstream
• Board-ready readout: delivered, in-flight, and year two pipeline

What a realistic prize looks like

For a UK business with £20-100m of addressable spend, a well-run 100 day plan typically lands its first run-rate savings by day 100, with more in the pipeline for months four to twelve. The result depends more on how much has been touched recently than on sector, and top-quartile procurement functions, the ones with genuinely disciplined category management, deliver 2.4x ROI and support 30% higher margins,^[3] which is the benchmark a plan like this is ultimately working towards.

Scaling business, rising costs and post-funding-round discipline

The 100 day plan is not only for post-deal or new CFO situations. Scale-up businesses hit a version of the same problem: revenue is growing but costs are growing faster, gross margin is drifting, and the founding-team habits that worked at £5m stop working at £30m. A post-funding-round cost discipline exercise applies the same 100 day sequence to a different starting point.

• Baseline the last 12 months of spend against revenue growth by category
• Identify categories growing faster than revenue, usually SaaS, marketing and professional services
• Introduce approval thresholds and PO discipline before headcount forces it
• Rebase supplier terms on scale-up volume rather than start-up urgency
• Stand up light procurement governance so the funding round is not spent inflating the base

For most scale-ups, this exercise buys 6-12 months of extra runway from the same balance-sheet position, without slowing hiring or product investment.

Where this connects

This overlaps directly with our cost reduction and interim procurement director work, and pairs well with the Earnings improvement guide.