设计变更的重测判定表怎么做

结论：把判断固化成表，比每次重新分析更快也更一致

产品上市之后会有持续的变更——改善工艺、降低成本、更换供应商、优化结构、修复问题。每次变更都要判断：需不需要重新测试？测哪些？要不要申报？

每次从头分析有两个问题： 一是费时，二是不同人判断可能不一致，同样的变更这次判要测下次判不要测。

把判断固化成一张表，列出常见的变更类型及对应的处理，判断就变成了查表，快且一致。

表不能覆盖所有情况，遇到表上没有的变更仍要分析，但分析的结果可以补充进表。

表的基本结构

一张可用的判定表大致包含这些列：

变更类型。 变更的分类。

典型情形。 该类型下的具体例子。

影响的特性。 这类变更通常影响什么。

需重测的项目。 对应要重做的测试。

可免测的说明要点。 如果申请免测，论证要说明什么。

申报处理。 需不需要申报、按什么级别。

审批层级。 这类变更由谁批准。

这七列覆盖了变更处理的主要决策点。

变更类型的划分

变更类型	典型情形
材料变更	牌号、供应商、配方
结构变更	尺寸、形状、壁厚、加强
工艺变更	成型方式、热处理、表面处理
部件变更	外购件的型号或供方
电气变更	元件、电路、布线
软件变更	功能、逻辑、参数
生产场地变更	换线、换厂
标识变更	铭牌、标签、说明书
包装变更	材料、结构
配置变更	选装件的增减

每个大类下再细分，因为同一大类中不同的变更影响差别很大——比如材料变更中，换供应商而牌号不变，与换成另一种材料，影响完全不同。

判定规则的制定

制定规则时的考虑：

从影响的特性出发。 变更影响什么特性，就重测与该特性相关的项目。

参考历史经验。 以往类似变更的处理和结果。

保守一些。 不确定时倾向于测，因为漏测的代价高于多测。

区分安全相关与否。 影响安全的从严，不影响的可以放宽。

考虑累积。 多次小变更累积后的影响。

「考虑累积」需要专门的机制。 每次变更单独看影响都不大，累积几次之后产品与原始状态差别明显。建议在表中加一条规则：累计变更达到一定程度时，做一次全面复测。

几类变更的处理示例

材料换供应商、牌号不变。 影响可能的配方差异。建议：做化学表征对比和关键力学性能对比；相关的生物相容性和阻燃项目考虑重做或论证。

结构尺寸小幅调整。 影响强度和装配。建议：受影响部位的强度验证；如果涉及受力路径，做整机强度和疲劳。

外购件换型号。 影响取决于部件的作用。建议：按部件的功能确定——承力件做强度，电气件做电气安全和 EMC。

软件版本更新。 按更新内容分类处理，前面专门讲过。

生产场地变更。 影响工艺一致性。建议：做首批产品的全项检验，并与原场地的数据对比。

标识变更。 通常只需核对标识内容的符合性。

表的使用流程

变更提出。 描述变更内容。

查表定类型。 确定属于哪个变更类型。

按表确定处理。 重测项目、申报要求、审批层级。

表外情形的分析。 表上没有的，做专门分析。

执行与记录。 按确定的处理执行并记录。

反馈更新表。 表外情形的分析结果补充进表。

「反馈更新表」是表持续有效的关键。 每次遇到新情形都补充，表会越来越完善，覆盖率越来越高。

表的维护

定期复核。 规则是否仍然合适。

标准更新时的调整。 适用标准变化可能改变重测项目。

新市场的加入。 各市场的申报要求不同，表中的申报列要覆盖各市场。

经验的积累。 实际执行中发现的问题反馈到表。

版本控制。 表本身是受控文件。

「各市场的申报要求」建议在表中分列，因为同一个变更在不同市场的申报义务可能不同，分列之后处理起来更清楚。

与实验室的配合

判定表中的重测项目，建议与实验室确认过：

项目的必要性。 实验室对影响的判断可能与企业不同。

项目的可行性。 有些项目可能需要特殊条件。

周期的估计。 便于安排变更的实施时间。

论证的要求。 申请免测时论证要写到什么程度。

建议把表拿给实验室看一遍，实验室从检测角度的意见能让表更实用。

判定表的一个示例片段

以材料变更为例，表中可以这样展开：

同牌号换供应商。 影响：配方差异。重测：化学表征对比、关键力学性能、阻燃。申报：按各市场规定。审批：技术负责人。

同类材料换牌号。 影响：性能与配方。重测：完整力学性能、阻燃、生物相容性、相关整机项目。申报：多数市场需要。审批：管理层。

换成不同类材料。 影响：全面。重测：按新材料重新评估全部相关项目。申报：需要。审批：管理层。

仅颜色变更。 影响：色母成分。重测：阻燃、生物相容性（或表征对比论证）。申报：多数市场备案。审批：技术负责人。

这样展开之后，具体到某次变更就能直接查到处理方式。

与供应商的配合

很多变更源于供应商，所以供方管理要配合：合同中约定变更告知义务；关键材料的变更需事前批准；以及定期核实供方是否有未告知的变更。

我们的做法

遇到变更后的复测委托时，我们会看委托方提供的变更说明和影响分析。如果委托方有判定表并按表确定了范围，沟通会很顺畅 ——我们只需确认判断是否合理。

如果没有说明，我们通常要建议较大范围的复测，因为无法判断影响。这对委托方并不划算。

我们也可以就判定表中重测项目的设定提供意见，从检测的角度说明某类变更通常影响哪些项目。

如果你在建立变更的重测判定规则，需要检测方面的参考，可以把表的草稿发过来一起讨论，或者直接联系：132 4819 8029。检测能力见服务介绍，产品分类见手动轮椅检测与电动轮椅检测，标准信息见标准查询。

English version

Conclusion. After launch, products undergo continuous change: process improvements, cost reductions, supplier substitutions, structural optimisation and problem fixes. Each change raises the questions of whether retesting is needed, which items, and whether notification applies. Analysing afresh each time has two drawbacks: it takes time, and different people judge differently, so the same change may be judged to need testing one time and not the next. Fixing the judgement in a table, listing common change types and their handling, turns judgement into a lookup that is both quick and consistent. A table cannot cover everything, and changes it does not cover still require analysis, but the results of that analysis can be added to the table.

Structure of the table. A usable table carries roughly these columns. Change type, giving the classification. Typical instances, giving concrete examples within the type. Characteristics affected, stating what such a change usually affects. Items to retest, listing the corresponding tests. Points for an exemption argument, stating what a justification must address. Notification handling, stating whether notification applies and at what level. And approval level, stating who authorises such a change. Those seven columns cover the main decision points in change handling.

Classifying changes. Material changes cover grade, supplier and formulation. Structural changes cover dimensions, shape, wall thickness and reinforcement. Process changes cover forming method, heat treatment and surface treatment. Component changes cover the model or supplier of bought-in parts. Electrical changes cover components, circuits and wiring. Software changes cover functions, logic and parameters. Manufacturing site changes cover moving lines or factories. Marking changes cover nameplates, labels and instructions. Packaging changes cover materials and construction. And configuration changes cover adding or removing options. Subdivide within each category, since effects differ greatly: within material changes, substituting a supplier while keeping the grade differs entirely from changing to another material.

Setting the rules. Work from the characteristics affected, retesting the items relating to them. Draw on history, reflecting how similar changes were handled before and what resulted. Lean conservative, testing where uncertain, since the cost of omission exceeds the cost of extra testing. Distinguish safety-related from other changes, being strict on the former. And account for accumulation across multiple changes. Accumulation needs a specific mechanism: each change looks individually minor while several together leave the product noticeably different from the original. Add a rule that once cumulative change reaches a defined level, a comprehensive retest is performed.

Handling examples. A supplier change with the grade unchanged may involve formulation differences; perform comparative chemical characterisation and key mechanical property comparison, and consider repeating or justifying biocompatibility and flammability items. A small dimensional adjustment affects strength and assembly; verify strength at the affected area, and if the load path is involved, perform whole-product strength and fatigue testing. A bought-in component substitution depends on the component's role; verify by function, with strength testing for load-bearing parts and electrical safety and electromagnetic compatibility for electrical ones. Software updates are classified by content, as discussed separately. A manufacturing site change affects process consistency; perform full inspection on the first batch and compare against data from the original site. And a marking change generally needs only verification of the marking content.

Using the table. A change is proposed with its content described. The type is looked up. The handling follows from the table, covering retest items, notification and approval. Cases outside the table receive dedicated analysis. The handling is executed and recorded. And the analysis of out-of-table cases feeds back into the table. That feedback is what keeps the table effective: adding each new case makes the table progressively more complete and its coverage higher.

Maintaining the table. Review the rules periodically for continued suitability. Adjust when standards change, since applicable standard revisions may alter retest items. Extend when markets are added, since notification requirements differ and the notification column must cover each market. Incorporate experience from problems found in execution. And control the version, since the table is itself a controlled document. Set out notification requirements by market in separate columns, since the same change may carry different obligations in different markets and separating them makes handling clearer.

Working with the laboratory. Confirm the retest items in the table with the laboratory. Necessity may be judged differently by the laboratory than by the manufacturer. Feasibility matters, since some items need particular conditions. Duration estimates help schedule change implementation. And justification expectations establish how thoroughly an exemption must be argued. Show the table to the laboratory: their perspective from the testing side makes it more practical.

How we handle it. For retesting after a change we review the change description and impact analysis the client provides. Where a client has a judgement table and has set the scope accordingly, communication is straightforward and we need only confirm whether the judgement is sound. Without such a description we generally have to suggest broader retesting, because the effect cannot be judged, which is not the best outcome for the client. We are also glad to comment on the retest items in a table, explaining from a testing perspective which items a given change type usually affects.

Send us a draft table and we will review it with you. Phone or WeChat: +86 132 4819 8029.