On the basis of the manufacturing execution system technical research of SOA
Plan the bridge between decision-making system and bottom layer process control system as enterprise’s upper strata, manufacturing execution system (MES) Play a more and more important role in such aspects as plan deployment, course management of production of the workshop. In quick to make it with the networked mode that makes nowadays, the traditional manufacturing execution system is difficult to meet product control of the workshop’s demands, mainly showing in the following aspects: a)Integrated difficulty. In design, develop, finish, set about solve and other the intersection of enterprise and the intersection of application system and Integrated problem and then usually, because the unitary standard and mature technical support of every application system of enterprises, extremely integrate the difficulty. b)Restructurability is bad. The tight coupling that generally adopted, stiff and fragile framework have often solidified most functions of the system, only my fraction can carry on the disposition of the parameter, it is difficult to guarantee the agility of enterprises, it is unable to support enterprises to meet the change of market and production environment fast. c)Development cycle is long. Traditional MES big, cycle with high costs long problem of generally customizing work capacity, have hindered MES from being applied to the enterprises and workshops of different types, characteristic.
Face and serve the framework (SOA) Manufacturing execution system last the ones open industrial standard,language independence, loosely-coupled, cross platform, good capsulation, position characteristic such as being transparent. These characteristic manufacturing execution system of making can on-demand meet an emergency in order to meet demand to make management fast. Facing the manufacturing execution system of serving the framework already becomes the focus studied, present research has not put forward comparatively intact facing and serving the system framework of the manufacturing execution system yet, analyze insufficiently about the function faced and served in MES integrating, disposition and commercialization. To the above-mentioned problems and current situations, this text has set up the facing and serving the technology system of MES on the basis of the key standard of SOA, further investigate and face the application in MES of critical technology serving.
1 faces the manufacturing execution system served
Face the manufacture serving and carry out the system architecture. Systematic presentation layer the intersection of human-computer interaction and interface of MES mainly, offer Web, many visit of way such as being wireless. The systematic platform storey includes enterprise’s database, workshop leave over system, application server and ISA95 field standard etc.. The component floor In Service, the business of the workshop, according to SCA (serve the component system) The norm is capsulated as the service of a series of thick graininess, these services are relatively independent. Include, reusable by oneself, its interface adopts neutrality, because of the canonial way. MES serves and carries on the mutual, call through serving the total wiring layer. The service procedure floor is with BPEL (the execution language of Business Process) And BPMN (business process modeling notation, the modeling symbol of the Business Process) It is a standard, serve compounding, editing to MES, the Business Process modeling of workshop of the end that the end gets by realizing and carrying out.
2 MES services based on SCA are designed and assembled
SCA is a kind of brand-new programming model that OpenSOA organization puts forward. It is the basic building block unit in SOA to serve the component, capsulates business function and logic rule of MES. Serve whom component it has to be kind than face target, pay most attention to efficiency, make MES can develop, implement fast in a manner to put up the building blocks. Serving the component divides MES service into the interface and realizes two parts. The service interface uses WSDL (web service description language, the description language of the Web Service) Describe all function methods and relevant information of this service. Serve, realize, serve, realize the way to the intersection of interface definition and function specifically, have the characteristic of cross platform, technology systems such as Java, C ++,etc. language and EJB, CORBA, .NET,etc. can all be regarded as the realization on component of MES service. For example, the automatic production schedule algorithm component offers the detailed production plan that the algorithm produces for MES system through the service interface, quote and serve and get task information, product information and process capability information,etc. to restrain from other MES as the algorithm through the interface. The realization of the service can be adaptation dispersed particle cluster algorithm, improved genetic algorithms, simulated annealing algorithms,etc., the language platform where the algorithm code adopts is unrestricted.
According to SCA norm, a plurality of related service components assemble and get MES service module (composite) . The service module is minimum arrangement unit MES, can promote and regard some interface of the component in module as one’s own service. A service module can realize and inlay sheath type assembly as the service of the component within another module. In the design development process of MES, are chosen appropriate assembly target, reasonable assembly way of design, can realize the function model of MES layering correspondingly.
MES is through serving capsulation and assembly of the component, has improved the graininess served, the putting in an position of convenient system. Take dispersed manufacture workshop of the aerospace system as examples, the typical MES service is as follows, a)Multi-layer production planning service. Distribute batch to and receive the batch production planning to the task one according to essential data such as main production planning and products, resource,etc., and further make the detailed production plan manually or automatically. b)Dynamic scheduling service. Distribute and process the task to work station or workers actually according to the production planning; Quality overproof, hot job, persons who coordinate quality inspector, craft of scheduling problem of equipment failure,etc. role appearing to the processing course produce exception handing. c)Machining state service. (workers) Receive, process task, report abnormal state that appear in the processing course, in process, submit finish; (controller) Revise the machining state directly if necessary, cut off or stop the current task. d)Supervisory service of quality. Inquire and record and process task examining, result which the director, army examine of first component three, make and count the analytic basis as the plan. e)Sign of the bar code / RFlD service. Inquire, manage to a codenumber or radio frequency card of resources such as the supplies, frock,etc.. f)The material in process tracks that serves. Position (work station, buffering area, storehouse) that lives in the material in process Carry on accurate positioning, in order to shorten turnaround time. In addition, also include such services as resource management, essential data, system integration, other association produce.
3 MES services based on bus line are integrated with system integration
In the traditional distributed MES framework, the interdependence, inseparable between every business function, result in reconstructing the difficulty, in that the call between the function components has clear directivity. The function component one URL be lasted revising or components whole to be waited for at the time of deletion, depend on the other parts of this component will run unusually. In addition, the component communication skill is often stationary too, the Transport Protocol mismatch of newly added component will hinder systematic reconstruction too, if EJB can only receive RMI, the component of the unable compatible JMS agreement.
Facing MES system serving adopts the bus line mode to integrate, register and manage various services in the system, and augmentability and compatibility of the security system. Serving the bus line mainly has two constituent elements: First, serve the registration table, keep and connect registration information of all services on bus line of this service; Second, serve the router, is responsible for the function of mapping in news transmitting, format conversion, agreement etc.. The core of serving the bus line thought is to serve consumers and loosely-coupled, transparent each other between the providers. , especially for serving the call across MES of the subsystem, service consumers can not be restricted (SOAP, EJB, JMS) in the agreement And needn’t understand provider’s prerequisite of the position, carry on with the service provider in the particular position of particular agreement mutually! Under total collinear support In Service, it will not cause the integral abnormal state of the system while adding, deleting, revising etc. and operating the function in the system according to the business demand of the workshop that MES employs. Integrate besides the internal service, serve the integration that buses can also support enterprise’s application systems such as MES and ERP, SCM, PDM,etc.. Other system call, and the service of other application systems of call that MES offers service for through serving the bus line, in order to realize the intersystem operation each other.
MES and ERP Integrated typical scene. Serve the bus line at first for ERP (serve consumers) And MES (service provider) Establish the inbound port with setting off separately. MES registration table release WSDL describe file In Service, ERP search behind the registration table to serve bus line, announce the intersection of request and message, hand MES in the router. MES receive after the request finishing service content, return along the opposite route by the intersection of response and message of production schedule including. In this scene, MES has provided the following services for ERP: The order progress controls and serves and takes charge of feedbacking the present production schedule information of some part products after ERP system sends out the service request; The supplies consumption feedbacks and serves and puts forward to ERP and concentrates on providing and delivering the requirement according to the result of comparison with production planning of stock feeling of the workshop supplies; The short-term production planning service offers task for some time at present to the workshop to arrange with the process capability state, as the basis of decision of the enterprise layer.
Tags: SOA
