# How the North Star Metric Skill Defines and Calculates Input Metrics in phuryn/pm-skills > Learn how the North Star Metric skill defines and calculates input metrics. Discover the 3-5 actionable leading indicators that drive your NSM, ensuring clear ownership and measurable goals. - Repository: [Pawel Huryn/pm-skills](https://github.com/phuryn/pm-skills) - Tags: how-to-guide - Published: 2026-07-07 --- **The North Star Metric skill defines input metrics as 3-5 actionable, MECE (mutually exclusive, collectively exhaustive) leading indicators that directly drive the NSM, calculated by identifying causal links to the primary metric, assigning ownership, and setting current and target values.** The North Star Metric skill in the `phuryn/pm-skills` repository provides a structured framework for product teams to identify their primary customer-centric KPI and map the specific input metrics that influence it. Located in the `pm-marketing-growth` package, this skill guides users through classifying their business game, validating metric candidates against seven criteria for effectiveness, and defining a constellation of actionable input metrics that explain exactly how the North Star moves over time. ## Understanding the North Star Metric Framework ### What Constitutes a North Star Metric According to the source code in [`pm-product-strategy/skills/product-strategy/SKILL.md`](https://github.com/phuryn/pm-skills/blob/main/pm-product-strategy/skills/product-strategy/SKILL.md), a **North Star Metric (NSM)** is a single metric that captures the core value a product delivers to its users. It must function as a **leading indicator** (such as "daily active users who complete a value-adding action") rather than a vanity or lagging metric like raw revenue. The NSM serves as the central gravitational point around which all product decisions orbit. ### The Three Business Game Classifications Before defining input metrics, the skill requires classifying the "business game" through the workflow defined in [`pm-marketing-growth/skills/north-star-metric/SKILL.md`](https://github.com/phuryn/pm-skills/blob/main/pm-marketing-growth/skills/north-star-metric/SKILL.md): - **Attention** – Products where primary value is user engagement and time spent - **Transaction** – Platforms focused on facilitating exchanges or purchases - **Productivity** – Tools that help users complete tasks or save time This classification determines which types of metrics are appropriate for the specific product context. ## How Input Metrics Are Defined and Calculated ### The MECE Principle for Input Metrics The skill mandates that input metrics follow the **MECE principle** (Mutually Exclusive, Collectively Exhaustive) as specified in [`pm-product-discovery/skills/metrics-dashboard/SKILL.md`](https://github.com/phuryn/pm-skills/blob/main/pm-product-discovery/skills/metrics-dashboard/SKILL.md). This means: - **Mutually Exclusive** – Each input metric measures a distinct lever without overlap - **Collectively Exhaustive** – Together, the 3-5 input metrics cover the complete set of drivers that move the NSM Each input metric must represent a concrete, actionable driver that product teams can directly influence. ### The Five-Step Definition Process The calculation and definition workflow, implemented in [`pm-marketing-growth/commands/north-star.md`](https://github.com/phuryn/pm-skills/blob/main/pm-marketing-growth/commands/north-star.md), follows this strict sequence: 1. **Classify the business game** – Determine if the product is Attention, Transaction, or Productivity-focused 2. **Generate NSM candidates** – Propose 2-3 possibilities and evaluate them against seven criteria for an effective metric 3. **Pick the NSM** – Select the single best candidate that captures true user value 4. **Define Input Metrics** – For each lever, document the causal link to the NSM, the owner, current value, and target value 5. **Validate** – Ensure inputs are MECE and that the NSM measures authentic user value, not vanity metrics ### Input Metric Structure and Ownership When the skill calculates and structures input metrics, it generates a specific schema that includes: - **Metric Name** – The specific lever being measured (e.g., "New creator sign-ups") - **Drives NSM By** – The explicit causal mechanism (e.g., "Increases weekly active creators") - **Owner** – The team or individual responsible for moving this metric (e.g., "Growth", "Product", "Ops") - **Current** – The baseline measurement (e.g., "1,200 /mo") - **Target** – The goal state (e.g., "1,800 /mo") ## Implementation in the phuryn/pm-skills Repository ### Skill Manifest and Command Wrapper The core logic resides in [`pm-marketing-growth/skills/north-star-metric/SKILL.md`](https://github.com/phuryn/pm-skills/blob/main/pm-marketing-growth/skills/north-star-metric/SKILL.md), which declares the skill's description, trigger phrases (e.g., "north star metric", "define north star"), and the step-by-step workflow. The **command wrapper** at [`pm-marketing-growth/commands/north-star.md`](https://github.com/phuryn/pm-skills/blob/main/pm-marketing-growth/commands/north-star.md) exposes this functionality via the `/north-star` CLI-style command used by the Claude plugin system. When invoked, the command parses user input, invokes the skill logic, and renders the response as a structured markdown report. ### Integration with the Metrics Dashboard The skill reuses the generic **metrics dashboard** data model from [`pm-product-discovery/skills/metrics-dashboard/SKILL.md`](https://github.com/phuryn/pm-skills/blob/main/pm-product-discovery/skills/metrics-dashboard/SKILL.md), ensuring consistency across product discovery and growth teams. This integration allows the North Star framework to align with broader metric monitoring systems, including health metrics and alerting protocols. ## Practical Usage Examples Below are examples showing how users invoke the skill and the structured output it generates when defining input metrics. Running the North Star command to generate the complete framework: ```markdown /north-star > I'm going to help you pick a North Star Metric and three supporting input metrics. > 1️⃣ **Classify the business game** – Are you building an attention-driven app, a transaction platform, or a productivity tool? > 2️⃣ **NSM candidates** – e.g., "Weekly active creators", "Monthly revenue-per-user", "Time saved per session". > 3️⃣ **Select the NSM** – "Weekly active creators" (captures value delivered to creators). > 4️⃣ **Input metrics** > | Input Metric | Drives NSM By | Owner | Current | Target | > |--------------|--------------|-------|---------|--------| > | New creator sign-ups | ↑ weekly active creators | Growth | 1,200 /mo | 1,800 /mo | > | Creator content uploads | ↑ weekly active creators | Product | 3,000 /mo | 4,500 /mo | > | Retention (30-day) | ↑ weekly active creators | Ops | 45% | 55% | ``` Defining input metrics after NSM selection: ```markdown /north-star input-metrics > Based on the selected NSM "Weekly active creators", here are three actionable input metrics: > • **New creator sign-ups** – the funnel entry point; increase acquisition spend. > • **Creator content uploads** – the amount of value creators add; improve onboarding flow. > • **30-day retention** – keeps creators engaged; refine product-led growth loops. ``` These outputs demonstrate how the skill transforms abstract strategic goals into concrete, owned, and measurable input metrics. ## Summary - The North Star Metric skill in `phuryn/pm-skills` defines input metrics as **3-5 MECE leading indicators** that directly influence the primary NSM. - Input metrics are calculated through a **five-step process** that includes business game classification, candidate validation against seven criteria, and explicit causal mapping. - Each input metric requires **specific ownership** (Growth, Product, Ops) and **quantified targets** (current vs. goal values). - The implementation spans [`pm-marketing-growth/skills/north-star-metric/SKILL.md`](https://github.com/phuryn/pm-skills/blob/main/pm-marketing-growth/skills/north-star-metric/SKILL.md) and [`pm-marketing-growth/commands/north-star.md`](https://github.com/phuryn/pm-skills/blob/main/pm-marketing-growth/commands/north-star.md), integrating with the shared metrics dashboard model. - The framework ensures input metrics are **actionable** rather than vanity measurements, providing product teams with clear levers to move their North Star. ## Frequently Asked Questions ### What does MECE mean in the context of input metrics? **MECE** stands for Mutually Exclusive, Collectively Exhaustive. According to the skill definition in [`pm-product-discovery/skills/metrics-dashboard/SKILL.md`](https://github.com/phuryn/pm-skills/blob/main/pm-product-discovery/skills/metrics-dashboard/SKILL.md), this means each input metric must measure a distinct lever without overlapping with others (mutually exclusive), while the complete set of 3-5 metrics must account for all major drivers of the North Star Metric (collectively exhaustive). This prevents double-counting and ensures comprehensive coverage. ### How many input metrics should a North Star Metric have? The skill specifies **3 to 5 input metrics** as the optimal range. This constraint ensures the metric constellation remains manageable and actionable while providing sufficient granularity to explain NSM movement. Fewer than three may miss critical drivers; more than five becomes difficult to track and own effectively. ### What are the seven criteria for validating a North Star Metric candidate? While the skill references seven criteria for an effective NSM in [`pm-marketing-growth/skills/north-star-metric/SKILL.md`](https://github.com/phuryn/pm-skills/blob/main/pm-marketing-growth/skills/north-star-metric/SKILL.md), the specific criteria are evaluated during the candidate generation phase. The criteria ensure the metric captures core user value, acts as a leading indicator, and aligns with business success. The skill workflow requires evaluating 2-3 candidates against these standards before final selection. ### Can input metrics be used independently of the North Star framework? While input metrics are technically defined within the North Star skill, they adhere to the **metrics dashboard data model** from [`pm-product-discovery/skills/metrics-dashboard/SKILL.md`](https://github.com/phuryn/pm-skills/blob/main/pm-product-discovery/skills/metrics-dashboard/SKILL.md). This means they can be monitored and tracked independently, though they derive their strategic significance from their causal relationship to the NSM. The skill specifically structures them to drive the North Star, not as standalone KPIs.