Availability

There's a difference between "on the payroll" and "actually free for work." Availability is the second one.

Someone's contracted for 160 hours a month, but they've got 3 days of vacation and a public holiday in there. Their real availability is closer to 128 hours. Schedule them for 160 and you've got a problem before the month even starts.

This sounds obvious, but most agencies track it poorly — or not at all. They'll check a shared Google Calendar, maybe ping someone on Slack ("Hey, are you around next week?"), and hope for the best. At 5 people, that works. At 15, it's chaos.

What Eats Into Availability

• Time off — vacation, sick leave, personal days
• Public holidays (these vary by country — easy to forget for distributed teams)
• Part-time schedules and reduced hours
• Recurring internal commitments — all-hands, retrospectives, 1:1s

The tricky part is that availability changes constantly. Someone approves a last-minute holiday request on Tuesday, and the allocations you planned on Monday are now short 16 hours. If your tool automatically deducts time off from capacity and flags the conflict, you catch it immediately. If it doesn't, you find out when the deadline slips.

Contractors Add Another Layer

Full-time staff default to 160h/month, but contractors might be available 60h one month and 120h the next. Capacity planning only works when each person's availability reflects their actual situation — not a one-size-fits-all assumption. Keeping per-person monthly capacity settings current is unglamorous work, but it's what separates a realistic forecast from fiction.