A forecast can reconcile perfectly, pass review and still describe a commercial position the business has already moved away from.

Forecasts can look reliable because they are built from approved budgets and committed purchase orders, with input from the business, reviewed at month end and reconciled without issue. The problem is that the position behind those numbers can change as a third-party services engagement develops.

Consider a third-party services engagement to deliver a business transformation programme, starting with an approved budget of £1M. At approval, there is a twelve-month plan, a defined scope of work, an experienced services supplier and a business case that has stood up to scrutiny. Based on the information available at the time, the engagement appears well governed and the £1M approval is reasonable.

Over the following eighteen months, the work develops and the cost increases. No single decision transforms the financial position, but a series of changes gradually moves the engagement beyond what was originally approved.

Procurement is usually closely involved when a requirement is defined, suppliers are evaluated, terms are agreed and the Statement of Work (SOW) is signed. The challenge is maintaining that same visibility and control through delivery, when scopes evolve, milestones move, additional work is requested and suppliers adapt to changing requirements.

For Procurement, closing the blind spot means managing the engagement as something that evolves, rather than something that is finished once the SOW is signed.

How an organisation manages its supplier-delivered services says more about its operational discipline than almost any other category of spend. 

When margins come under pressure, most efficiency programmes reach for familiar levers such as headcount and other category budgets. Third-party services spend rarely receives the same attention, despite being one of the largest costs many organisations carry and, in many cases, one of the least controlled. 

These were public bodies with established processes and resources, yet both still faced significant liabilities. For private organisations, the lesson goes beyond IR35. Third-party services are commissioned across multiple functions, suppliers and systems, while the decisions behind them can be spread across the business. When something goes wrong, having a process is not enough. You need to be able to show what was bought, why it was approved, how it was managed and what has changed since. 

By the time a third-party services overrun becomes visible, the opportunity to prevent it has often already passed. 

Large supplier-delivered services engagements rarely exceed their budget because of a single decision. They drift over time as scope evolves, requirements change and delivery adapts. Individually, those changes often appear reasonable, but collectively, they can fundamentally alter the commercial profile of an engagement. By the time the full impact becomes apparent, the budget has already shifted, and the forecast has become increasingly difficult to recover. 

Most organisations can report, with a high degree of accuracy, what they spent on outsourced services last year. Far fewer can demonstrate, with the same confidence, what that investment actually delivered. 

It's a question that sounds deceptively simple: 

“For everything we spent on third-party services like consultancy, IT, engineering and business transformation, what did we actually get in return?” 

An outsourced supplier engagement comes to an end, the final invoice is paid, and the project is signed off. Yet months later, members of the supplier's delivery team may still have access to business systems, sensitive information or company facilities because that access was never formally removed. In many organisations, no one can say with confidence exactly how often this happens or how many former supplier personnel still retain access they no longer need. 

Ask most businesses how many individual contractors they have working for them right now, and they can usually get an answer in minutes. Ask what the business is getting in return for the millions it spends on third-party services, whether projects are on track and whether they are delivering the outcomes they were paid to achieve, and the answer is often far less certain. That gap is where services spend can become a black hole, where organisations know what they are spending but struggle to see whether that investment is translating into business outcomes.  

When an organisation buys goods, suppliers can generally be compared on specification, quality and price. Contingent labour follows a similar principle, where value is closely linked to the rate paid for an individual's time and materials. Services procurement operates differently. Two suppliers may submit proposals at almost identical prices yet deliver very different outcomes. The price captured within the Statement of Work (SOW) and ultimately reflected in the purchase order (PO), says little about the value the organisation will achieve. 

One of the biggest levers leaders have on cost, risk and speed is also one of the least understood at board level. 

Every executive team is judged on the same handful of things: protecting margin, controlling risk, and moving fast enough to stay ahead. One of the largest levers on all three sits in a part of the business that rarely reaches the boardroom is how an organisation buys, governs and manages the services it depends on. 

Many organisations view services procurement as an extension of contingent workforce management. It's an understandable assumption as both involve engaging external suppliers, bringing in specialist expertise, and managing non-employee spend, so it feels natural to reach for the same systems and the same playbook for each. 

However, while the two disciplines may appear similar on the surface, they are solving fundamentally different problems for different work delivery channels. Treating one as a version of the other is where many processes run into difficulty. 

A Statement of Work (SOW) is often misunderstood as simply a contract document used to engage external services. In reality, an SOW is the contractual framework through which services procurement engagements are defined, managed and measured typically sitting beneath a Master Services Agreement (MSA) that governs the broader commercial relationship.  

Services procurement and contingent workforce management are often discussed together because both involve external resources. However, they operate under fundamentally different models, with different stakeholders, governance structures, and objectives.