These four models answer four different questions: how much of a senior person do you need, for how long, who directs the work, and who owns the outcome. Pick on those four and the choice mostly makes itself.
The short answer. Hire fractional when you need senior judgment on a function but not a full-time seat. Bring in an interim executive when a seat is empty or in crisis and needs a full-time leader for a bounded stretch. Use staff augmentation for scarce or temporary skills that you will direct yourself. Make a direct hire when the seat is core, permanent and full-time.
The four models side by side
| Dimension | Fractional | Interim | Staff augmentation | Direct hire |
|---|---|---|---|---|
| Time commitment | Part-time, often a few days a week or month | Full-time for the engagement | Full-time or part-time, set by the vendor contract | Full-time |
| Typical duration | Months to years, and it can run indefinitely | Short and defined, commonly one to six months | Temporary, project-based or unpredictable demand | Open-ended, a long-term commitment |
| Who employs them | Self-employed or independent; often serves several companies | Independent or placed through a firm | A vendor supplies external talent | Your payroll, with compensation and benefits |
| Who directs the work | They own the function's judgment and priorities within a defined scope | They take the full role, including day-to-day management | You direct the work day to day | The employee, inside your org chart |
| Typical trigger | You need senior judgment but not a full-time seat | A departure, a transaction or a crisis | Scarce or temporary skills, extra capacity | A core, permanent seat |
| Cost shape | Monthly retainer; Hunt Scanlon cites roughly $5,000–$15,000 a month at one to two days a week | Higher total cost for the full-time load; may be lower per hour (BPM) | Higher bill rate, lower fixed overhead (Proxify) | Higher fixed cost, usually lower long-term cost per unit of output (Proxify) |
| Main risk | Used as a permanent substitute for a leader the seat really needs | The role outlasts the interim and no plan exists for the permanent hire | Knowledge and IP stay with the vendor's people | Slow to fill and slow to reverse |
Fractional: senior judgment, not a full-time seat
A fractional executive works part-time, typically across several clients, and owns the judgment and direction of a function inside an agreed scope. BPM describes fractional engagements as tending to run longer than interim ones, and as usually proactive: building a cash-flow model, preparing for a raise, setting up reporting. It fits the company that needs a seasoned CFO, CMO or COO in the room, but not forty hours a week of one.
Interim: a full-time leader for a bounded stretch
An interim executive takes the whole role, including day-to-day management, for a short and defined period, commonly one to six months. BPM frames it as the reactive option, the response to an unexpected departure, a transaction or a crisis. The cost is higher in total because the commitment is full-time, though it can be lower per hour than a fractional arrangement.
Staff augmentation: capacity you direct
With staff augmentation a vendor supplies external talent and you keep day-to-day direction. Proxify describes it as suited to temporary, specialized or unpredictable demand, with a higher bill rate and lower fixed overhead than a payroll hire. It is most common for technical and project capacity. It is a poor stand-in for an executive, because the person is executing your plan, not helping you decide it.
Direct hire: the permanent owner
A direct hire is on your payroll with full compensation and benefits. Proxify notes higher fixed costs but usually lower long-term cost per unit of output, and stronger control over IP and institutional knowledge. It is the right answer when the seat is core and the work is continuous, and the slowest and hardest to reverse when you are wrong.
The expensive mistake is rarely picking a model that is too costly. It is picking one built for a different problem.
Where the math flips
Hunt Scanlon (Sept. 1, 2026) reports fractional executives at roughly $5,000 to $15,000 per month for one to two days a week, and puts the break-even with full-time at about three days a week of real need. Past that point a full-time hire costs somewhat more but owns the outcome. If your honest estimate of the work is three or more days a week, every week, start looking at the permanent seat. If it is one to two, fractional is usually the better fit.
The models work in sequence
These are not exclusive. BPM notes that a business may use an interim leader to handle a crisis and then a fractional executive for ongoing support. A common version of that sequence: an interim leader stabilizes the seat, a retained search finds the permanent hire, and a fractional executive stays on a narrower scope while the new leader settles in.
What this is not
This is not a ranking. None of the four is the best model, and a cheaper line item does not mean a better fit. It is not a case against full-time leadership either. Fractional is a bridge or a bounded scope, not a structure for a seat that needs a permanent owner. And ETHOSLINK is not a staffing company: we do not place hourly contingent workers. We run retained executive search and place fractional executives, and we will tell you when a different model suits you better.
If you are weighing two of these for the same seat, our pieces on fractional versus full-time and retained versus contingency search go deeper on each side, and the fractional executive roles we place are listed by function.