Criteria for Splitting an Amoeba

Overview

• What you’ll learn: The three conditions that justify splitting a group into an independent amoeba — and why violating any one of them produces either administrative chaos or unaccountable bloat.
• Estimated reading time: 10 minutes

Introduction

The Grand Historian records: Before the army can march, the commanders must draw the boundaries. A battlefield with no unit designations is not a battle — it is a mob. Inamori Kazuo, designing the amoeba system for Kyocera in the 1960s, faced the same question every organizational architect faces: where do you cut? The answer is not intuitive, and the wrong answer costs more than the question.

Split too finely and you manufacture administrative burden — each micro-unit requires its own monthly P&L, its own leader, its own internal pricing arrangements. A ten-person company divided into eight amoebas spends more time in accounting than in production. Split too broadly and the accountability that makes the amoeba system valuable evaporates. A fifty-person amoeba has fifty places to hide a bad decision.

Inamori’s answer is three conditions, all of which must be satisfied simultaneously. Not two out of three. All three.

The Three Conditions

• Independent revenue generation: Can the unit generate measurable revenue — either from external customers or via internal transfer pricing to other amoebas? If all revenue flows through another unit with no internal price assigned, there is no P&L to manage. The unit is a cost center, not an amoeba.
• Clearly assignable costs: Can the direct costs of this unit be identified without ambiguous allocation? Labor is usually traceable. Shared equipment, shared space, and shared administrative support often are not. If more than 30% of the unit’s costs require arbitrary allocation, the numbers lose credibility and the unit time profit metric becomes fiction.
• Team size of 3–10 people: Below three, the administrative overhead of a separate P&L exceeds the accountability benefit. Above ten, the unit grows large enough that individual accountability begins to diffuse. The range is not arbitrary — it corresponds to the natural upper limit of a single leader’s direct operational attention.

In Practice

Before proposing any split, map three columns on paper: revenue sources (internal and external), cost items (direct and allocated), and current headcount. If the revenue column is empty or entirely dependent on another unit’s decisions, reconsider the split. If the cost column contains more allocated items than direct items, reconsider. If headcount is outside the 3–10 range, either wait until the unit grows or combine it with an adjacent group.

The most common error is splitting based on organizational convenience — “the marketing team and the sales team have different managers, so they should be separate amoebas.” Managerial convenience is not a sufficient condition. Revenue independence and cost clarity are the actual tests.

Key Takeaways

• All three conditions must be satisfied: independent revenue, assignable costs, team of 3–10.
• Too small = administrative overhead exceeds accountability benefit.
• Too large = individual accountability diffuses.
• Organizational convenience is not a valid split criterion.