triz-intermediary

# TRIZ Intermediary (Principle #24) ## Overview Intermediary is one of Genrich Altshuller's 40 Inventive Principles from TRIZ (Theory of Inventive Problem Solving), derived from analysis of over 200,000 patents. The principle states: use an intermediary carrier article or intermediary process to enable, improve, or protect the interaction between two elements. The core insight: when direct interaction is impossible, inefficient, or harmful, introduce a third element to mediate the relationship. The intermediary can transform, translate, buffer, or optimize the connection without requiring changes to the original elements. Intermediary appears in three forms: 1. **Physical Intermediary** - An object that enables physical connection (adapters, couplers, buffers) 2. **Process Intermediary** - An agent or service that facilitates interaction (brokers, translators, routers) 3. **Temporal Intermediary** - A mechanism that manages timing mismatches (queues, caches, schedulers) ## When to Use - Two elements cannot connect directly due to incompatibility - Direct interaction would damage one or both elements - The interaction needs translation, transformation, or buffering - Modifying the original elements is impractical or expensive - You need flexibility to change one element without affecting the other - Distribution, aggregation, or routing is required - Safety concerns prevent direct contact ## The Process ### Step 1: Identify the Direct Interaction Challenge What prevents or degrades direct connection between the two elements? **Example:** Vacuum cleaner motor generates high suction but cannot navigate tight spaces. ### Step 2: Define Intermediary Requirements What must the intermediary do to solve the interaction problem? **Requirements Categories:** - **Physical Translation:** Size, shape, material compatibility - **Property Transformation:** Voltage conversion, speed reduction, pressure regulation - **Routing/Distribution:** One-to-many, many-to-one, selective routing - **Protection:** Shield from heat, chemicals, electrical discharge - **Temporal Buffering:** Absorb timing mismatches, smooth bursts **Example:** Intermediary must be flexible to navigate corners while maintaining suction. ### Step 3: Design or Select the Intermediary Choose the simplest intermediary that meets requirements. **Example:** Flexible hose with internal ribbing for structural integrity. ### Step 4: Optimize Interface Points Ensure clean, efficient connection at both ends of the intermediary. **Example:** Standardized coupling at motor end, swivel joint at attachment end. ### Step 5: Test End-to-End Performance Verify that the intermediary enables the desired interaction without introducing new problems. **Example:** Measure suction loss through hose, test durability under repeated flexing. ## Example Application **Situation (Software Onboarding Complexity):** New users struggle with complex software setup, leading to high abandonment rates. **Application:** 1. **Direct Challenge:** New user lacks knowledge to configure 30+ settings correctly 2. **Intermediary Requirements:** Guide user through decisions without overwhelming them 3. **Intermediary Design:** Step-by-step onboarding wizard with contextual help 4. **Interface Optimization:** - Start screen with single "Get Started" button - Completion screen with "Launch Application" transition 5. **Testing:** A/B test shows wizard reduces abandonment from 40% to 12% **Outcome:** 70% reduction in support tickets during first week, 28% increase in successful onboarding completions. ## Anti-Patterns - Adding intermediary when direct connection is actually possible - Choosing an intermediary that is more complex than the problem - Creating bottlenecks through slow or limited-capacity intermediaries - Failing to maintain or upgrade the intermediary as needs evolve - Over-relying on intermediaries instead of fixing underlying incompatibilities - Introducing intermediaries that add latency or reduce quality unacceptably - Not providing fallback when intermediary fails ## Related - adapter-pattern (software design pattern for interface compatibility) - proxy-pattern (intermediary object controlling access to another) - mediator-pattern (centralized coordination between multiple elements) - translation-layer (transform data/protocols between systems) - buffer-abstraction (temporal intermediary for rate mismatches)