There are lots of articles researching on pull system model, which often neglecting the defect of parts or assuming the defect level equals to zero directly in production process.

关于拉式系统模型的研究文献很多，但它们往往忽略生产过程零部件缺陷的存在或者直接假设缺陷水平为零。

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Figure 13: By graphing "Severity" of defect against "time" to close, we see that some Level 1 defects have taken time to be resolved.

图13：通过描绘缺陷“严重级别”与关闭“时间”关系的图表，我们可以看到一些严重水平为1的缺陷已经花时间解决了。

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Fourth, there are no defect attributes that describe users' feelings, so developers can never know the customer satisfaction level until after release.

第四，这里并没有描述用户感情的缺陷，因此开发者根本不知道顾客的满意水平，一直到发布以后。

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"If, in future, this child should develop Parkinson's, or cancer, Alzheimer's or a heart defect, by that time technology would have progressed to such a level that you could then use these stem cells to fight or even cure these illnesses, if they arise, " she said.

BBC: NEWS | UK | Northern Ireland | Mother's stem cell hopes for baby