giving a specification, doesn't means you can build the product, regardless who have the job. If I just give you a spec, then stop talking to you. There is no way you can follow the spec and do the work. You will have different interpretation of the spec, you will have questions. If those questions don't get answers, and I do not participate in the review the requirements you development, you think you can design the system? What makes 中国的民营企业 so different? The law of physics don't apply to them?