--- title: The Hardware Store and the Cost of Software Maintenance description: An analogy between buying hardware store bolts and calculating software maintenance cost leads to a proposed formula: Cognitive Cost = Complexity * (Churn *... canonical: https://daily.dev/posts/the-hardware-store-and-the-cost-of-software-maintenance-yomfxy2jq twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: The Hardware Store and the Cost of Software Maintenance | daily.dev og:description: An analogy between buying hardware store bolts and calculating software maintenance cost leads to a proposed formula: Cognitive Cost = Complexity * (Churn *... og:url: https://daily.dev/posts/the-hardware-store-and-the-cost-of-software-maintenance-yomfxy2jq og:image: https://api.daily.dev/og/posts/yOmFXY2JQ.png og:image:alt: The Hardware Store and the Cost of Software Maintenance og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # The Hardware Store and the Cost of Software Maintenance **[RUBYLAND](https://daily.dev/sources/rubyla)** · 6 min read · 0 upvotes · 0 comments ## Summary An analogy between buying hardware store bolts and calculating software maintenance cost leads to a proposed formula: Cognitive Cost = Complexity * (Churn * Exposure), where Complexity comes from the ABC metric, Churn is the number of changes to a file over time, and Exposure is the inverse of test coverage. Worked examples across several hypothetical files show how this can highlight which files consume the most engineering mental energy, and how extracting complexity from a heavily-changed, poorly-tested file can theoretically free up significant team capacity. The author explicitly labels this an untested theory and invites others to try it. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [The Cost of Change in Software](https://daily.dev/posts/the-cost-of-change-in-software-zgqnzhu9w) · Ruby Flow · 0 upvotes · 0 comments - [How Complex is my Code?](https://daily.dev/posts/how-complex-is-my-code--kxokcsmfp) · Hacker News · 2 upvotes · 0 comments - [How Thrivability ROI Tackles the Cognitive Load Crisis](https://daily.dev/posts/how-thrivability-roi-tackles-the-cognitive-load-crisis-isru7nlyb) · The New Stack · 0 upvotes · 0 comments - [Cognitive Load](https://daily.dev/posts/cognitive-load-ibssi6s3p) · Wawandco · 0 upvotes · 0 comments --- Tags: [#testing](https://daily.dev/tags/testing), [#technical-debt](https://daily.dev/tags/technical-debt) [View this post on daily.dev](https://daily.dev/posts/the-hardware-store-and-the-cost-of-software-maintenance-yomfxy2jq) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"The Hardware Store and the Cost of Software Maintenance","url":"https://daily.dev/posts/the-hardware-store-and-the-cost-of-software-maintenance-yomfxy2jq","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/the-hardware-store-and-the-cost-of-software-maintenance-yomfxy2jq"},"datePublished":"2026-08-20T05:55:35.452Z","dateModified":"2026-08-20T05:55:53.291Z","description":"An analogy between buying hardware store bolts and calculating software maintenance cost leads to a proposed formula: Cognitive Cost = Complexity * (Churn *...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/7c8ee4324a0d387d4d64956992ff3cbe?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/7c8ee4324a0d387d4d64956992ff3cbe?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"RUBYLAND","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"RUBYLAND","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/rubyla","url":"https://daily.dev/sources/rubyla"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/the-hardware-store-and-the-cost-of-software-maintenance-yomfxy2jq","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"testing,technical-debt","timeRequired":"PT6M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"RUBYLAND","item":"https://daily.dev/sources/rubyla"},{"@type":"ListItem","position":3,"name":"The Hardware Store and the Cost of Software Maintenance"}]} ```