Mars Slough Investment Turns Chocolate Heritage Into Digital Manufacturing

Mars is using a historic UK factory as a platform for next-generation confectionery manufacturing. In its official announcement, the company said it is investing GBP190 million in its Slough factory, home to brands including Mars, Galaxy and Snickers.

The investment began in 2023 and runs through to 2028, with GBP32 million still planned for 2027 and 2028. The source is older than the newest wire releases in this run, but it is a strong manufacturing story: advanced machinery, robotics, AI, cooling systems, utilities, workforce skills and export supply all sit inside one factory programme.

A heritage site with a new brief

Slough is not a greenfield plant. Mars says the factory dates back to 1932 and remains closely tied to the history of the Mars bar. That makes the investment commercially interesting. Instead of moving all innovation to a new site, Mars is modernising an established asset with deep brand, labour and supply-chain roots.

The site produces for the UK and also supplies chocolates to Ireland and the Netherlands. That export role matters because a confectionery factory has to balance domestic demand, regional supply and the operational complexity of multiple product lines. Investment in one site can therefore affect service levels beyond its local market.

For retailers, the question is whether the upgrade supports more reliable availability, better quality consistency and faster response to demand shifts. For co-packers, machinery suppliers and ingredient partners, the signal is that large confectionery groups are still willing to put capital into mature Western European manufacturing when the plant has strategic value.

Digital manufacturing enters chocolate

Mars says the investment introduces robotics, AI, upgraded machinery, advanced cooling systems and energy-efficient utilities. The release also points to digital twin technology that uses AI-driven data to optimise production, improve process control and support real-time decision-making on the factory floor.

Chocolate manufacturing is a demanding environment for this kind of work. Temperature control, line speed, ingredient consistency, forming, cooling, wrapping and quality checks all have to be tightly managed. A small process variation can affect texture, appearance, waste or throughput. That makes digital tools attractive if they can improve consistency without slowing production.

Digital twins can be especially useful where physical trial-and-error is expensive. If a plant can model process changes before applying them, it may reduce waste and shorten the path from engineering decision to stable production. The trade value sits in better process confidence, not in the technology label itself.

Skills are part of the capital plan

The release links physical upgrades with workforce upskilling, including routes into advanced engineering, automation, data and AI-enabled manufacturing roles. That matters because food manufacturers cannot modernise factories through equipment alone. They need operators, engineers and maintenance teams who can interpret data, manage automation and troubleshoot more complex systems.

For the wider food industry, this is one of the hardest parts of the transition. Factories are becoming more digital, but many plants still depend on practical knowledge held by experienced teams. The strongest upgrade programmes will combine new systems with structured training so that the workforce can use the technology rather than work around it.

Mars also places the Slough project inside wider UK and global investment, including capital spending across snacking, food and petcare businesses. That broader context shows that manufacturing capability is being treated as a strategic asset, not only a cost centre.

Commercial angle

The commercial angle is that legacy factories can still become strategic growth assets if the investment is targeted. Mars Slough has brand heritage, existing labour capability, regional supply relevance and enough scale to justify advanced manufacturing systems.

For confectionery suppliers, the opportunity sits in automation, cooling, packaging, digital controls and engineering services. For ingredient suppliers, more sophisticated production can create tighter specification demands. For retailers, a better-invested factory can support availability and quality in categories where brand trust and impulse purchase remain essential.

Checklist for confectionery manufacturers

• Which legacy sites have enough strategic value to justify major reinvestment?
• Can digital twin tools reduce process variation and waste in chocolate production?
• Are cooling systems, utilities and packaging lines upgraded together rather than separately?
• Does the workforce plan match the new automation and data requirements?
• Will investment improve regional service levels as well as site efficiency?

Mars’ Slough programme shows that confectionery manufacturing is entering the same digital and resilience conversation as newer food categories. The best factories will not only make familiar brands. They will use data, automation and skills to keep those brands competitive.