Cohort hiring plan: recruit 15 people for one start date
Plan backwards from a shared start date. This 15-person hiring example calculates applications, interview slots and recruiter time before the deadline.
Adan Vielma · · 12 min read
You have hundreds of applications and need 15 support staff to start training together. The manager has reserved eight interviews a week for three weeks: just 24 appointments. Is that enough to get 15 people through hiring in time?
Work backwards from the people you need on day one, then reserve time for every hiring stage. Fifteen starters can be translated into a plan for CV reviews, interviews and offers. It also shows why attracting more applicants will not help until you fix the interview calendar.
Start with the people you need on training day
A hiring cohort is a group recruited to join together, often for shared training. Fifteen support staff must start on Monday, 7 December 2026. The business has approved 15 jobs and the training team has 15 places. The rates and review times are planning assumptions, not hiring benchmarks.
The target is people who actually start, not offers sent, offers accepted or candidates marked hired. Keep each person’s agreed start date and any outstanding conditions beside their name.
Agree whether 15 is a target or the minimum needed to run training. The answer determines what you must decide if the class is not full.
How many interviews and applications do you need?
Start with 15 people joining. If your planning assumption is that 90% of accepted offers become starts, divide 15 by 90% and round up: 17 acceptances. Then ask how many offers you need to get those acceptances. Repeat that step back through the process.
Required count = next-stage target ÷ expected conversion rate, rounded up. In Excel or Google Sheets, =ROUNDUP(22/50%,0) gives 44 interviews for 22 offers. Use 50% or 0.5, not 50, for the rate.
Read down the table from 15 starters to the applications needed to support them:
| Work backwards from… | Assumption | Number to plan for |
|---|---|---|
| Actual starters | The business needs 15. | 15 |
| Accepted offers over the campaign | 90% of acceptances become starts: 15 ÷ 90%, rounded up. | 17 |
| Offers over the campaign | 80% of offers are accepted: 17 ÷ 80%, rounded up. | 22 |
| Completed manager interviews | 50% lead to offers: 22 ÷ 50%. | 44 |
| Completed first screens | 50% lead to completed manager interviews: 44 ÷ 50%. | 88 |
| First-screen invitations | 80% are completed: 88 ÷ 80%. | 110 |
| Applications | 25% receive an invitation: 110 ÷ 25%. | 440 |
Do not add the rows: the same people appear at successive stages. Count a retry as another attempt, not another applicant. A person applying to two vacancies can still fill only one place in this class.
These are estimates of work across the campaign, not instructions to offer more jobs than exist. The 17 acceptances could include replacements after people withdraw. With 15 approved jobs, track outstanding commitments before making another offer.
The calculation does not show whether those replacements can finish hiring and start in time. Check that separately in the calendar; extra applications cannot make a late withdrawal happen earlier.
Calculate interviewer capacity, including unused slots
The original calendar has 24 appointments, but the plan calls for 44 completed interviews. You are at least 20 appointments short.
Allow for appointments that do not produce a completed interview. At an assumed 80% completion rate per reserved slot, you need 55 slots: 44 ÷ 80%. A cancellation may leave an hour empty, and a rescheduled candidate may need a second booking. That is why the slot count exceeds the candidate count.
If a second interviewer takes a separate set of 8 appointments each week, the team has 48 slots over 3 weeks. That is still below the 55-slot allowance.
Include preparation and written feedback. A 45-minute interview plus 15 minutes of preparation and notes requires a one-hour block: 55 reserved hours for one assessor per session. You may recover some cancelled time, but should not assume you can reuse every late cancellation.
A two-person panel is different. Reserving 55 one-hour appointments for both assessors takes 110 staff-hours, but still gives you only 55 candidate appointments. Adding someone to the same interview does not double the number of people you can assess.
Check your CV review capacity as well. Reading 440 CVs at 2 minutes each takes 14 hours 40 minutes. Reviewing 88 first-screen reports at 4 minutes each adds 5 hours 52 minutes. That is 20 hours 32 minutes before scheduling or candidate messages. Check your team's actual review pace before using those estimates.
Reserve enough time before building the calendar
Ask two qualified interviewers to take separate appointments, each reserving 10 one-hour slots a week for 3 weeks. That provides 60 slots, including preparation and feedback. At the assumed 80% rate, you would expect 48 completed interviews against the target of 44.
Agree the assessment standard before dividing the work, then book the time. Two people agreeing to help is not the same as 60 appointments reserved.
Put dates and responsibilities next to the counts
These dates illustrate a 2026 campaign; move the linked milestones to fit your intake. Manager interviews can start as soon as the first screens are reviewed; the whole group need not be ready at once.
In this calendar, some applicants must finish screening before the first manager appointments on 5 October. The 9 October target is the deadline for the main invitation batch, not the day screening begins. Check each week's appointments against the people expected to be ready. An empty slot in the first week does not become extra capacity in the last.
| Work | Example timing | What must be available | Responsible person |
|---|---|---|---|
| Review applications and invite | Main invitations sent by 9 October. | Review time for 440 applications, 110 invitations and enough time for each person to respond. | Recruiter |
| Review completed first screens | Throughout the period; main decisions by 16 October. | 88 completed screens, review time and answers to important clarifications. | Recruiter and screening reviewer |
| Manager interviews and decisions | 5–23 October. | 44 completed interviews, with an allowance of 55 slots. Confirm the proposed 60-slot calendar is booked. | Hiring manager |
| Offers, responses and required checks | Initial target: 30 October. | Offer approval, candidate response time and enough time to complete the required checks. | Recruiter and HR |
| Confirm readiness | Review on 27 November; keep checking until start. | Each person's confirmed availability, outstanding conditions, equipment and training arrangements. | HR and training lead |
| Training starts | 7 December. | Approved positions and support for the people actually arriving. | Operations lead |
Test this calendar against actual notice periods. An applicant needing eight weeks cannot resign after 30 October and finish that notice before 7 December. Their acceptance may still be valuable, but it does not fill a place in this intake until the timing is resolved.
The same applies to checks and approvals. If they need more time than this schedule allows, begin them at the appropriate stage, finish decisions earlier or revise the start plan.
Keep a candidate's notice estimate separate from an agreed start. Clarify their notice period and any release still to be agreed. Do not back-calculate a date that requires someone to resign before the offer is ready.
What to change when the team cannot spare that time
Add interview capacity. Find qualified colleagues who can assess the same requirements. Agree how they will judge answers before splitting the work. Check what their calendars can realistically support, including preparation and feedback.
Start earlier or allow more weeks. At 8 slots a week, 6 weeks provides 48 slots and 7 weeks provides 56. Check that applicants will be ready to use the earlier appointments and that later offers still leave enough time for notice.
Remove repeated assessment. If two stages ask the same questions, decide whether one can do the job. Keep a clear place to assess each essential skill, and recalculate the rates for the revised process rather than assuming the old ones still apply.
Change the intake. A smaller first class or a second start date may be more realistic. The business and training team must agree, and candidates need accurate information about the change.
Raising a cutoff until the shortlist fits 24 slots does not create more hiring capacity. It can simply hide people you should consider.
A 90% start rate is not a 90% chance of a full class
“Nine out of ten people usually start” does not mean a group of 15 will usually arrive in full. To see why, assume each of 15 accepted candidates has a 90% chance of starting, independently of the others.
Multiply 0.9 by itself 15 times: the chance that all 15 start is about 21%. Across many such groups, the average would be 13.5 starters. This calculation illustrates NIST's binomial probability model, not a measured forecast for your intake.
Real candidates have different notice periods and commitments. Shared problems, such as delayed offer approvals, can affect several starts together. The 21% calculation assumes equal, independent probabilities; do not use it as your forecast unless those assumptions are justified.
Turn that uncertainty into a decision: when will you decide whether to run a smaller class or move the intake? Track delays affecting the whole group, as well as each person's notice and outstanding checks, so the business can act before training day.
Do not over-promise jobs to cover predicted withdrawals
Ask the person approving offers to confirm how many places remain available. Include accepted offers and offers still awaiting a reply. Predicted withdrawals do not make those places free to promise to someone else.
A last-minute withdrawal may also leave too little time to hire a replacement. Keep the smaller-class or later-intake decision available instead of assuming every empty place can be filled before training.
Do not promise 17 jobs and plan to withdraw two offers if everyone arrives. Singapore’s MOM guidance on contracts cancelled before the start date says both parties should be prepared to fulfil a signed employment contract. In Great Britain, Acas explains that accepting an offer can create contractual obligations, depending on its terms. Have HR review any proposed change to a commitment; a forecast of withdrawals is not permission to cancel someone’s job.
A waitlist can help maintain contact with interested people, but it is not a guarantee of replacements. Be clear:
We have completed your assessment, but do not currently have a place in the 7 December intake. May we contact you if one becomes available? This is not a job offer, and we cannot promise a place. We will update you by [date]. Please continue with other opportunities in the meantime.
Follow your retention and contact rules. Do not ask someone to remain available indefinitely for a possible vacancy.
Test what happens if fewer candidates accept or start
Keep the target at 15 starters and vary the assumptions. The three scenarios show the workload if more or fewer people reach the next stage. They do not assign a probability to each outcome.
| Conversion or required count | Favourable | Base | Adverse |
|---|---|---|---|
| Acceptance → start | 95% | 90% | 80% |
| Offer → acceptance | 90% | 80% | 70% |
| Completed manager interview → offer | 60% | 50% | 40% |
| Completed first screen → completed manager interview | 60% | 50% | 40% |
| Invitation → completed first screen | 90% | 80% | 70% |
| Application → invitation | 30% | 25% | 20% |
| Manager interviews needed | 30 | 44 | 70 |
| Applications needed | 187 | 440 | 1,250 |
Round up at every stage. The adverse case needs 19 acceptances, 28 offers, 70 completed manager interviews, 175 completed first screens, 250 invitations and 1,250 applications.
Even the favourable case needs 30 completed manager interviews. The original 24-slot calendar is too small in all three scenarios.
Use comparable, completed hiring rounds to estimate your rates, and record the counts behind them. Keep pending decisions separate: someone still considering an offer is not a decline, and an open response window is not a failed invitation.
Where you have little history, keep a range of scenarios rather than treating one precise percentage as established. The useful question is whether the plan still works when the assumptions worsen.
Update the remaining work each week
At the next review, 12 manager interviews are finished, 20 are booked and 12 applicants still need appointments. You have completed 12 of the planned 44, leaving 32 interviews to finish. A booking is progress, but not a completed assessment.
At the same 80% assumption, those 32 completions need an allowance of 40 remaining slots. Twenty are booked. The other 20 cover the 12 people awaiting an appointment and room for bookings that need repeating.
Check the decisions from the first 12 interviews too. If they produced more or fewer offers than expected, recalculate the remaining work. The target of 44 interviews is a forecast, not a quota to complete after the hiring need is met. Honour the review process advertised to applicants, and explain any authorised closure rather than quietly abandoning the remaining queue.
Keep a start list alongside the totals. A useful note is: “Dev accepted the offer, but 7 December depends on an earlier release from the current employer. Dev will confirm by 27 November; Riley will follow up that day.” Count Dev as an accepted offer with timing unresolved, not a confirmed starter.
Check whether that follow-up leaves time to act. If 27 November would be too late to arrange a replacement, agree what the business will do about the possible empty place earlier.
Request interview capacity and a fallback start plan
For the initial plan, the useful manager update is:
Our working assumptions give us a target of 44 completed manager interviews for the 7 December intake. Allowing for unused appointments, we need 55 one-hour slots. We currently have 24.
Can you and a second qualified interviewer each reserve 10 separate one-hour appointments a week for 5–23 October? That would give us 60 slots. We also need roughly 21 hours for CV and report reviews, plus time for scheduling and messages. If that time is unavailable, we need to agree a different start plan.
Only 15 jobs are approved. Please also confirm whether training can run with fewer people, or whether we would arrange another intake. We must not promise extra jobs to cover possible withdrawals.
After the manager decides, reserve the time and assign each deadline. In the weekly review, ask what is finished, what is waiting and what could stop someone joining on time. Raise that obstacle while the team can still change the plan.
