The task of hiring good people is loaded with either/or options: extroverts versus introverts, hunters versus farmers, Myers-Briggs ISTPs vs. INTP’s, and so on. But one of the most important A or B decisions businesses will make today is between hiring a consultant or an interim – especially when a major change initiative is underway.

You might think this is a false dichotomy. After all, interim managers and consultants will both have high-level intellectual capabilities and offer specialist skills and services. When a change initiative goes live however, what you get in terms of support can be dramatically different.

The same is true for the cost. With so much at stake it’s crucial for hirers to understand the comparative benefits of interims, and not allow ‘hire a consultant’ to become a default setting.

Call it the thinkers vs. doers binary. Whilst both types of short-term hire come into a project role prepared to advise and propose solutions, interims bring a hands-on bias. After analysing the situation and making plans, their natural next steps is to make the proposal happen.

Consultants, on the other hand, excel at devising a number of viable alternative solutions, then leave it to the client to choose one, translate it into a critical path, and see the plan through to reality. Their proposals are often academic in tone and approach, with recommendations about methodology but not on the nitty gritty of implementation.

Consultancy has established a well-earned prestige and reputation for quality which can’t be ignored. But when the objective is to see concrete action on a defined timeline, bringing in an interim manager with the additional nous and experience to implement a project is the better option.

Rise of the supertemp

Today’s interims are top managers and professionals—from CIOs to CFOs, to software architects and senior developers—who’ve been trained at best universities and largest global corporates. They choose to pursue project-based careers independent of any major firm and they’re increasingly trusted by organisations to do mission-critical work — jobs that in the past would have only been trusted to permanent employees.

Today’s consultants, on the other hand, may be amongst the best & brightest, but it’s an open question whether they have the front line experience to deliver as well as propose.

To lead change agendas successfully you need proven hands to sanity check any strategic proposal and lead its implementation based on real world experience. It’s not something for novices or recently qualified MBA’s. Rather it’s for the wizened veterans with twenty of so years of business experience and the requisite battle scars that come with seeing things not go exactly to plan.

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The management consultancy model doesn’t allow for a deep bench of supremely qualified interim managers; people who are basically on-call, able to manage change, crisis and all the requisite uncertainty they bring on, in some cases, very short notice.

In fact interims can be used to challenge the potential costs of management consultancy, and take back control over change programmes. Sitting within the management team, an experienced interim manager can drive implementation, transfer their knowledge, and then exit when the time is right, ensuring that the organisation is on a footing to continue seamlessly without them.

Access to the best talent is another reason interim is better for temporary or project hires. Consulting firms can’t offer the best senior-level interim managers in the market because most interims remain deliberately independent, and only represented by firms that specialise in their skill sets or service.

All of those factors have made the interim offer compelling enough to tempt some of the big consultancies to dip their toes in. McKinsey, for example, is experimenting with an interim Recovery & Transformation Services practice which is very focused on implementation.

But can a leopard that big really change its spots? Experience tells me the cost effectiveness and emphasis on experienced, strategic doing at the outset of an engagement means that the interim model is going to win out every time.

Rorie Devine is the former CTO of Betfair and Hailo, and is now the founder and CEO of interim.team.