Why New Hires Leave in the First 90 Days
Research on early attrition consistently identifies the same causes: the new hire did not understand what was expected of them, their manager was not adequately prepared to support their ramp, and the onboarding experience did not match what was described during the interview process. These are not personality fit problems or hiring mistakes. They are process failures — and they are preventable with a structured onboarding programme built before the new hire starts.
The cost of early attrition compounds every other cost in the hiring process. The recruitment cost — whether that is agency fees, job board spend, or internal recruiter time — is lost entirely. The productivity the role was supposed to deliver never materialises. The team absorbs the work of an unfilled position a second time. And the process restarts with a team that has lower morale and a hiring manager who is more risk-averse than before. According to SHRM research, replacing an employee costs on average between 50% and 200% of their annual salary depending on seniority and specialism.
An AI onboarding agent eliminates the structural causes of early attrition by building a complete onboarding programme before day one — tailored to the specific role, the specific hire, and the specific team context.
What Most Onboarding Programmes Actually Look Like
In most organisations, onboarding is the last thing prepared before a new hire starts. The hiring process absorbs all the energy. Once the offer is accepted, the manager's attention shifts back to the existing workload. The new hire's first week is assembled from whatever the previous person in the role received, whatever HR can schedule, and whatever the manager can spare time for.
The result is a first week dominated by laptop setup, HR admin, compliance training, and a series of introductory meetings with no clear purpose. The new hire leaves week one unsure what their first real task is, who the most important people in their network are, and what success looks like in their first month. These are entirely avoidable gaps — and they are the gaps most likely to produce an early departure.
Onboarding Starts Before Day One
Simon — the KissMySkills onboarding agent — builds pre-boarding materials as the first component of every programme. The period between offer acceptance and start date is when anxiety is highest and competing offers are most dangerous. A new hire who has not heard from their new employer in the two weeks since accepting can easily be re-engaged by a competitor, or arrive on day one with doubts that the pre-start experience did nothing to address.
The pre-boarding package Simon produces includes a welcome email sent within 24 hours of acceptance acknowledging the decision and setting the tone; a pre-start checklist covering what the new hire needs to do, know, and prepare before they arrive; clear communication about what day one will look like so there are no logistical surprises; and introductions to key team members before the start date so the new hire walks in knowing at least some faces. This is the difference between a new hire who arrives excited and one who arrives anxious.
First Week: Connection, Clarity, and an Early Win
The first week schedule Simon produces is built around three deliberate priorities. Connection: meeting the people the new hire needs to know — not everyone, but the colleagues, stakeholders, and cross-functional contacts most important to their success in the first 90 days. Clarity: understanding the role, the team's current priorities, how success is measured, and what the manager expects in the first month. And an early win: completing something concrete and visible that makes the new hire feel effective by the end of week one rather than week three.
This balance is deliberate. It addresses the most common first-week complaint — "I spent the entire week in compliance training and HR admin" — while ensuring the new hire has the context and connections to actually perform once the structured onboarding ends. The first week schedule Simon produces is day-by-day with named meetings, suggested topics, and the purpose of each interaction explained.
30/60/90-Day Plan: Outcomes, Not Activities
Most 30/60/90-day plans are lists of activities. "Complete compliance training." "Meet all team members." "Review Q3 strategy document." These are easy to produce and easy to complete without any real indication of whether the new hire is actually ramping. Simon builds outcome-based plans — what the new hire should know, what they should be doing independently, and what they should have delivered by each milestone.
By day 30, the new hire understands the role, the team, and the most important current priorities. By day 60, they are making independent contributions to their core responsibilities. By day 90, they are operating at full productivity on the primary job functions and have built the relationships they need to be effective long-term. Each milestone is specific, measurable, and relevant to the actual role — not a generic template applied to every new hire regardless of function or seniority.
The plan is agreed between the manager and new hire at the start — not handed down as a performance requirement. The difference matters. A 30/60/90-day plan that the new hire helped shape is a shared roadmap. One that is handed to them is a monitoring framework. Simon's output includes a conversation guide for how to introduce and co-own the plan effectively at the start of employment.
Separate Checklists for HR, Manager, and New Hire
Onboarding fails when responsibility is ambiguous — when everyone assumes someone else has handled the systems access, the team introduction, or the first performance conversation. Simon produces three separate checklists with no overlap and no gaps. The HR checklist covers administrative, compliance, and systems setup responsibilities. The manager checklist covers the relational, strategic, and development responsibilities that only the manager can fulfil — the role context conversation, the expectation setting, the 30-day check-in. The new hire checklist covers what the new starter needs to do, access, read, and complete during their own ramp.
Each owner knows exactly what they are accountable for, when it needs to happen, and what a completed item looks like. Ambiguity is the most common reason onboarding tasks fall through the gaps — the checklists remove it entirely.
How to Build an Onboarding Programme with Simon
Load the Simon skill file into Claude Projects. Paste the activation prompt. Simon asks intake questions about the role, the team, the new hire's background, the manager's style, and when the new hire starts. The more context provided, the more role-specific and useful the output. Simon produces the complete programme — pre-boarding pack, first week schedule, outcome-based 30/60/90-day plan, and three separate checklists — in one session. Simon works with Claude, ChatGPT, or any AI chat that accepts system prompts.