Concession (Tokusai): A Controlled Deviation or a Structural Risk?
逸脱は違反ではない ― しかし、管理されなければならない
本章では、「Concession（特採）」という概念を整理します。
製造業において、逸脱が発生すること自体は異常ではありません。
現実の工程では、
•材料のばらつき
•設備の微小な変動
•測定誤差
が常に存在します。
問題は「逸脱の存在」ではなく、
それをどのように管理するかです。
ISOベースの品質マネジメントでは、
•非適合の識別
•技術評価
•承認プロセス
•記録とトレーサビリティ
が制度として組み込まれています。
特採は、基準を緩める仕組みではありません。
リスクを可視化し、責任を明確化するための仕組みです。
本章では、物語から一歩離れ、
制度としての特採がどのような意味を持つのかを整理します。
ここを理解すると、物語で起きていることの輪郭がより鮮明になります。
For readers unfamiliar with manufacturing, the concept of a “Concession” (Tokusai) may appear to be a minor technical procedure. In reality, it is a critical control point within a quality management system—where engineering judgment, documentation discipline, and organizational culture intersect.
⸻
1. What Is a Concession?
In manufacturing, every component must conform to defined specifications—dimensions, material properties, performance tolerances.
When a part fails to meet those requirements, the default action is rejection.
However, in certain cases, a nonconforming item may be evaluated and judged to be fit for use under defined conditions. When formally approved, this decision is referred to as a Concession (in Japanese practice, Tokusai).
The purpose of a concession is not to lower standards, but to manage risk rationally.
Typical justifications include:
•The deviation does not affect safety or functionality
•The deviation is cosmetic or marginal
•The risk has been evaluated and accepted
However, a concession is only legitimate when it follows structured controls.
⸻
2. Concession Under ISO-Based Quality Systems
Under ISO 9001 and related standards (such as IATF 16949 in automotive sectors), concessions fall under the broader framework of control of nonconforming outputs.
Key requirements typically include:
1.Identification
The nonconforming item must be clearly identified to prevent unintended use.
2.Evaluation
Technical assessment must determine the impact of the deviation.
3.Authorization
Approval must be granted by designated authority—often Quality Assurance or a Material Review Board (MRB).
4.Documentation
The concession must be recorded, including:
•Description of deviation
•Risk assessment
•Decision rationale
•Traceability (which products contain the material)
5.Traceability
The organization must retain the ability to track affected products in case of field issues.
The critical principle is this:
If it is not documented, it does not exist within the system.
The system relies not only on engineering logic, but on recorded accountability.
⸻
3. Variation in Organizational Culture
While the formal structure of concession control is globally recognized, its execution depends heavily on organizational culture.
In some environments, experienced engineers play a visible role in deviation decisions. Their judgment may be technically sound, but the risk arises when documentation discipline weakens.
In highly system-driven organizations, digital workflows and software controls restrict material release unless formal approval pathways are completed.
Neither approach is inherently superior.
The true risk emerges when:
•Risk is assessed informally
•Approval is implied but not recorded
•Responsibility becomes diffuse
At that point, the concession ceases to be a controlled deviation and becomes a structural blind spot.
⸻
4. The Structural Risk: When Deviation Meets Interaction
A properly handled concession assumes that the deviation is stable under expected operating conditions.
However, the story introduces a more complex phenomenon: conditional fragility.
The materials in question passed basic evaluation under standard environmental conditions.
Yet under high humidity—when interacting with environmental factors—the defect rate spiked.
This is where statistical interaction becomes critical.
A deviation that appears minor under one condition may become severe under another.
If such conditional risk is not anticipated, the concession mechanism itself can become a multiplier of instability.
Not because it is inherently unethical—
But because its assumptions were incomplete.
⸻
5. Concession and Organizational Power
In the story, what matters is not merely the presence of concessions, but the way they are handled.
If deviation decisions are:
•Recorded transparently
•Reviewed by multiple functions
•Evaluated against environmental variability
then the system remains robust.
However, if documentation becomes selective, and deviation decisions are confined to a narrow circle of discretion, a secondary structure may emerge—
Not illegal.
Not necessarily malicious.
But increasingly insulated from scrutiny.
Such insulation alters power dynamics.
A deviation decision, once shared transparently, becomes a managerial instrument when handled privately.
In that moment, quality control shifts from risk management to authority management.
⸻
6. Connection to the Story
In this narrative, the issue is not that concessions exist.
The issue is that:
•Their documentation pathway appears inconsistent
•Their interaction risk was not fully evaluated
•Their release aligns precisely with statistically unstable periods
The danger is not visible collapse.
The system continues to function.
Products ship.
Reports remain internally coherent.
But when structural risk is layered quietly over environmental sensitivity, the margin of safety narrows invisibly.
That narrowing—rather than any dramatic violation—is the true tension in this story.
制度は中立である。しかし運用は中立ではない。
特採は本来、合理的なリスク管理手段です。
しかし、制度そのものが中立であっても、
その運用は常に人間の判断に依存します。
•記録するかどうか
•どこまで共有するか
•誰が承認するか
これらの選択は、組織文化を反映します。
特採が透明に扱われている限り、
それは効率と安全を両立させるための道具です。
しかし、もし記録と実態の間にズレが生まれたとき、
その制度は別の機能を持ち始めます。
逸脱を管理する仕組みが、
逸脱を覆い隠す仕組みに変わることがある。
その境界は、法令違反ではなく、
“説明可能性”の有無にあります。
物語はまだ結論を出していません。
しかし、ひとつだけ確かなことがあります。
制度があるだけでは十分ではない。
制度が、どのように使われているか。
そこに、構造の真実が現れます。
