Industry 4.0 describes a smart job shop as follows: it can meet individual customer requirements even if the requirements are changed at the last minute; its production control system (PCS) can rapidly respond to unexpected disruptions in production, and smart workpieces in the smart job shop can communicate with workstations to tell them what to do next. Present PCSs issue production instruction (PI) to workstation in a relatively long period such as a day, a week, even a month. And the PI is usually at process level, which means it is not sufficient to maintain smooth production flow at the operational level. Therefore, the existing PCSs cannot meet the requirements of Industry 4.0. On account of this, this article proposes a smart workpiece enabled production instruction service system for smart job shop under Industry 4.0. The PI service system in smart job shop consists of three parts such as PI sets generation, PI sets execution and PI sets update. In PI sets generation, the PI is viewed as a service requirement from the smart workpiece for the workstation, and then a PI service model is established to integrate machining actions with different kinds of manufacturing resources, processing place and processing time. Based on that, a method of converting the Gantt chart to PI sets is presented. In PI sets execution, a PI service unit is proposed for real-time issuing PIs to the radio-frequency identification (RFID) tags of smart workpieces. In PI sets update, the update of PI sets including unexecuted processes PI sets and current processes PI sets is discussed in detail. Finally, a small-scale smart job shop is taken as an example to illustrate the feasibility of the PI service system.

工业4.0对智能车间的描述如下：即使在最后一刻更改了需求，它也可以满足单个客户的需求；其生产控制系统（PCS）可以快速响应生产中的意外中断，并且智能车间中的智能工件可以与工作站进行通信，以告诉他们下一步该怎么做。当前的PCS在相对较长的时间内（例如一天，一周甚至一个月）向工作站发布生产指令（PI）。而且，PI通常处于流程级别，这不足以在操作级别上保持平稳的生产流程。因此，现有的PCS不能满足工业4.0的要求。有鉴于此，本文提出了一种适用于工业4.0下智能车间的智能工件支持生产指导服务系统。智能作业车间中的PI服务系统由三部分组成，例如PI集生成，PI集执行和PI集更新。在生成PI集时，将PI视为来自智能工件的工作站服务要求，然后建立PI服务模型以将加工动作与不同种类的制造资源，加工地点和加工时间集成在一起。在此基础上，提出了一种将甘特图转换为PI集的方法。在执行PI集时，提出了一个PI服务单元，用于向智能工件的射频识别（RFID）标签实时发布PI。在PI集更新中，详细讨论了PI集的更新，包括未执行的流程PI集和当前流程PI集。最后，