Method and system for controlling a manufacturing plant with a manufacturing execution system

Abstract

A manufacturing plant with an MES system is controlled through the execution of a given workflow. a) A plant designer application models a representation of the manufacturing plant through a set of equipment objects and through a workflow, b) a complex entity (plugin) is provided for expanding the characteristics of an equipment object; the plugin exposing an interface with a configuration, a set of property elements, a set of functionality elements; c) at engineering time, designing a set of plugins usable by the set of equipment objects; d) at engineering time, for at least one equipment object, associating at least one plugin; e) defining, through the plant designer, a given workflow according to given customer requirements, the workflow including an interaction with an element of a plugin associated with an equipment object; f) at runtime, executing the given workflow and performing the interaction with the element of the plugin.

Claims

1. A process for controlling a manufacturing plant with an MES (manufacturing execution system) system, through an execution of a given workflow meeting given customer requirements, the process comprising: providing an application for modeling a representation of the manufacturing plant through a set of equipment objects and through at least one workflow, the application being a plant designer and an equipment object of the set of the equipment objects being a collector of information, wherein the set of the equipment objects are not object classes; expanding, with a complex entity, characteristics of the equipment object of the set of equipment objects, the complex entity being a plugin and the plugin exposing an interface including a configuration, a set of property elements, and a set of functionality elements, wherein the expanding of the characteristics of the equipment object includes at least adding a new property to the equipment object; performing the following steps at engineering time: designing a set of plugins usable by the set of equipment objects; for at least one equipment object of the set of the equipment objects, associating at least one plugin of the set of the plugins; through the plant designer, defining the given workflow accordingly to the given customer requirements, the given workflow including at least one interaction with at least one element of the at least one plugin associated with the at least one equipment object; and performing the following step at runtime: executing the given workflow and performing the at least one interaction with the at least one element of the at least one plugin associated with the at least one equipment object.

2. The process according to claim 1, wherein the at least one equipment object is a record of a database table.

3. The process according to claim 1, wherein the interface comprises an event element.

4. The process according to claim 1, wherein, when the at least one element of the at least one plugin is a functionality, the at least one interaction is a call to a functionality of the set of the functionality elements.

5. The process according of claim 1, wherein, when the at least one element of the at least one plugin is a property, the at least one interaction is an action of assessing the property.

6. The process according of claim 1, wherein, when the at least one element of the at least one plugin is a property, the at least one interaction is an action of raising the event.

7. The process according of claim 1, wherein an operation in the given workflow is a maintenance operation.

8. The process according to claim 1, wherein the at least one plug-in raises an event that indicates a completion of an operation in the given workflow.

9. A system for controlling a manufacturing plant with an MES system, through an execution of a given workflow meeting given customer requirements, the system comprising: an application for modeling a representation of the manufacturing plant through a set of equipment objects and through at least one workflow, said application being a plant designer, wherein the set of the equipment objects are not object classes; an equipment object of the set of the equipment objects being a collector of information; a complex entity for expanding a characteristic of the equipment object of the set of the equipment objects, wherein the expanding of the characteristic of the equipment object includes at least adding a new property to the equipment object, the complex entity being a plugin; the plugin exposing an interface including a configuration, a set of property elements, and a set of functionality elements; the system further comprising the following means to be used at engineering time: means for designing a set of plugins usable by the set of equipment objects; for at least one equipment object of the set of the equipment objects, means for associating at least one plugin of the set of plugins; through the plant designer, means for defining the given workflow according to the given customer requirements, the given workflow including at least one interaction with at least one element of the at least one plugin of the set of plugins, wherein the at least one plugin is associated with the at least one equipment object; and the system further comprising the following means to be used at runtime: means for executing the given workflow and performing the at least one interaction with the at least one element of the at least one plugin associated with the at least one equipment object.

10. The system according of claim 9, wherein an operation in the given workflow is a maintenance operation.

11. The system according of claim 9, wherein the at least one plug-in raises an event that indicates a completion of an operation in the given workflow.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) FIG. 1 is a block diagram schematically illustrating, in an exemplary embodiment of the present invention, how plugins may be placed inside a fragment of a plant model;

(2) FIG. 2 is a block diagram schematically illustrating, in an example embodiment of the present invention, how the functionality inside a plug-in can be executed from a workflow;

(3) FIG. 3 is a block diagram schematically illustrating, in an example embodiment of the present invention, the execution of a plugin method and the subsequent raise of a plugin event.

DETAILED DESCRIPTION OF THE INVENTION

(4) At least some embodiments of the present invention address the above described issue in which a manufacturing plant is controlled with an MES system, through the execution of a given workflow meeting given customer requirements.

(5) An application, called plant designer, is provided for modeling a representation of the manufacturing plant through a set of equipment objects and through at least one workflow.

(6) An equipment object is a collector of information, preferably it may be in form of a record of a table of a database, where each field may conveniently define a given equipment property.

(7) A complex entity, called plugin, is provided for expanding the characteristics of an equipment object. The plugin exposes an interface comprising a configuration, a set of property elements, a set of functionality elements and, optionally, a set of events.

(8) In particular:

(9) The configuration enables the system engineer to define the plug-in behavior, e.g. which functionalities, properties and/or events are exposed in the plugin; the properties are the parameters to be used for runtime I/O operations; the functionalities represent the plugin capabilities, also called methods; the events may be used for detecting changes happening outside the plant environment or for notifying changes inside the plant.

(10) At engineering time, it is designed a set of plugin usable by the equipment objects.

(11) At engineering time, for at least one equipment object is associated at least one plugin.

(12) At engineering time, through the plant designer, it is defined a given workflow according to given customer requirements. The given workflow comprises at least one interaction with at least one element of at least one plugin associated to an equipment object.

(13) At runtime, the given workflow is executed and it is performed the at least interaction with the at least one element of the at least one plugin of the associated equipment object.

(14) The action of interacting or interaction with the at least one plugin element may be one of the following, according to the involved type of element of the plugin: when the plugin element is a functionality, the interaction is the action of calling the functionality; when the plugin element is a property, the interaction is the action of assessing the property; when the plugin element is an event, the interaction is the action of firing the event;

(15) In invention embodiments, the set of plugins may preferably be developed using a common programming language and/or they may conveniently be packaged as a library, e.g. in the Windows environment as Dynamic Library or Static Library. In this manner, it is enabled the optimization of the logic execution and the developers and system engineers are provided with a user friendly language.

(16) In invention embodiments, the plugin base structure may preferably be designed so as to be self-describing, meaning that the configuration, the properties, the functionalities and, optionally, the events may conveniently be not real elements but mere descriptors. Advantageously, having such structure, compared to a hard-coded one, is characterized by a higher degree of flexibility, both from the developer side and the final integrator/system engineer side. By having a descriptor structure and not an hard-coded one, a plug-in can conveniently be developed in order to evolve and change depending on the user request. For instance, adding a new property to the equipment object becomes a simple task, e.g. adding a property descriptor inside the list of properties exposed by the plugin.

(17) The equipment object is not an object class, it does not have functionalities. Its functionalities are called thorough the plugin associated to the equipment object.

(18) A plugin has advantageously a status, the state of all its property, and may optionally have a memory. Hence it is an entity that can change status and, in case a memory is present, it may remember such status changes, e.g. in a plugin for material movement, it can be tracked where the material was moved from.

(19) In addition, in embodiments of the present invention, a real time representation of the plant may advantageously be achieved without needing to access the database, e.g. a representation of the bindings among PLCs (Programmable Logic Controllers). For example, the status of each equipment, the state of all its properties, may be updated using a plugin, called Automation plugin, which links it with the information exposed by an HMI (Human Machine Interface) working directly on the PLC Layer. In such example, it is not required to have a place for storing data for retrieving it, since all the information are stored in the RAM and are accessed combining the equipment and the Automation plugin.

(20) FIG. 1 is a block diagram schematically illustrating, in an example embodiment of the present invention, how plugins may be placed inside a fragment of a plant model.

(21) Block CELL-A represents an equipment object at “Cell” level, following ISA95 naming convention. The units UNIT-1, UNIT-2 and UNIT-3 represent equipment objects.

(22) To equipment object UNIT-3 are associated three plugins, one for “AUTOMATION MANAGEMENT,” one for “MAINTENANCE MANAGEMENT” and one for “WHAREHOUSE MANAGEMENT.” The “MAINTENANCE MANAGEMENT” plugin exposes an interface with following four elements: two methods or functionalities called “SearchitemById( ) and “MoveMaterialByName,” one property or attribute called “ItemsStored” and one event called “OnMovedMaterial”.

(23) FIG. 2 is a block diagram schematically illustrating in an example embodiment of the present invention how the functionality inside a plug-in can be executed from a workflow.

(24) Between the start ST and the end END of the workflow WF of FIG. 2, there is an interaction with an element of a plugin, in form of call to a plugin method.

(25) First the system engineer chooses the equipment object UNIT-3, then she/he selects the MAINTENANCE MANAGEMENT plugin and finally she/he selects the method SearchItemByID( ) DO to be executed.

(26) FIG. 3 is a block diagram schematically illustrating, in an example embodiment of the present invention, the execution of a plugin method and the subsequent raise of a plugin event.

(27) In a simple example embodiment, an equipment object representing a mixer piece may preferably be associated with an “Automation Field Management” plugin for enabling the communication with the relevant PLC. In addition, let us assume that such mixer equipment piece needs also to be maintained. Thus, to the mixer equipment object is also associated a “Maintenance Management” plugin so as to enable the access to all the functionalities used in a typical maintenance situation. This equipment object, with all the plugins associated and configured, may then conveniently be used in the definition of higher-level logics, such as rules or workflows.

(28) Such configured equipment object exposes for example the method “CheckAndDoMaintenance”, which is called by a workflow each time the maintenance period is due, as follows: the engine executing the workflow, called Workflow Executer, starts the workflow until it encounters the interaction with the plugin element, the call the method or functionality “CheckAndDoMaintenance” of the “Maintenance” plugin, e.g. in a .NET environment via reflection. the “Maintenance” plugin connects to a maintenance service performing the required operation; at the operation completion, the maintenance service communicates the result to the maintenance plugin, which raises an event “OnMaintenanceCompleted” the workflow executor catches the event and, if the maintenance is successful, the workflow arrives to the end END.

(29) Since the maintenance plugin has a status, it can also be configured for example as status “Ready”, or as a property “To_be-maintained in 5 days”. Advantageously, by using a plugin, a maintenance property needs not to be defined in the equipment objects since some objects may not require any maintenance. Instead, with embodiments of the invention, a plugin for maintenance may be conveniently associated to a given set of equipment objects.

(30) In addition, with a maintenance plugin, all the properties and functionalities linked to maintenance are grouped in a compact manner.