I. Introduction
Information technology is an effective means for enterprises to achieve modern management and enhance their technological capabilities. As a key design stage for product logic control, the necessity of information data integration in electrical design is self-evident. However, based on my experience of over ten years in the industry, very few companies have successfully integrated information technology into their electrical design processes. The root cause lies in the fact that the electrical design process has not adopted a digital model, but rather remains at the level of drawing documents (primarily DWG and Excel files). This model limits information management to managing results, preventing it from delving into the design process and the product lifecycle.
PDM tools require the digitization of design data when managing the entire design lifecycle of a product.
The new generation of electrical design tools integrates databases, enabling object-oriented management. Taking TraceSoftware International's elecworks as an example, the software uses Microsoft SQL Server as its database to store and manage elecworks data. This digital model provides possibilities for enterprise information management.
This article explores information integration solutions for electrical design, using elecworks and PTCWindchill as intermediaries.
II. System Construction Goals
The main objectives of electrical information integration fall into two categories: product lifecycle management and product BOM structure management.
Like a human life, every product goes through a development, growth, maturity, and decline phase. Product lifecycle management involves recording and managing all data throughout this process. In electrical design, there are inherently clear goals for establishing such a system.
1. Establish a complete design process. Standardized operating procedures need to be developed at different stages;
2. Establish a sound error-checking mechanism to create a closed loop between design and error checking, effectively reducing design errors;
3. Parametric and modularize the design process to reduce the degree of human intervention and lower the risk of generating basic errors.
With product lifecycle management, the BOM (Bill of Materials) structure cannot be built using PDM (Product Data Management) tools. Instead, it must be generated at the design stage and integrated into the PDM system. In other words, the electrical design phase should begin and complete the BOM structure construction during the product design process; for PDM, it's simply a matter of importing this structure, not recreating it.
III. System Architecture and Business Logic
1. Electrical design business logic based on elecworks
1) Electrical Design Process
Traditional electrical design involves processing existing DWG drawings, a method known as "graphics-oriented" design. Electrical engineers manually counted components using Microsoft Excel. In the early 21st century, this approach was phased out and replaced by database-based tools. For example, elecworks uses Microsoft SQL Server to manage all data, creating a new conceptual "database" within the software.
The database is divided into a symbol database and an equipment model database. A single piece of equipment (such as a relay) may be composed of multiple symbols (coils, contacts, etc.) or multiple equipment models (relays, mounting bases, etc.). In this way, after completing the electrical design, the database can automatically calculate parameters such as the quantity and brand of each equipment model used. Besides automating statistical work, another widely praised feature of the database is its reusability. The database only needs to be created once and can be reused an unlimited number of times, greatly reducing the workload of manual data entry.
With the help of the "library," electrical engineers can focus on design while the computer automatically compiles various data. Another feature of Elecworks is the interrelation of data, enabling data exchange between different design stages. For example, equipment wiring diagrams can be automatically generated and updated based on the design schematic. In this way, the general workflow shown in Figure 1 is formed based on Elecworks.
Figure 1 General Electric Design Flow
Different companies have different electrical design processes, which need to be adjusted according to the company's actual situation. For example, in a scanning equipment manufacturing company (hereinafter referred to as Company A), the electrical design engineers use the optimized workflow shown in Figure 2 when using elecworks.
Figure 2. Optimized design flow
In the optimized design process, the data for the design BOM (for electrical components with long procurement cycles, such as circuit breakers) is already determined during the project quotation stage in Company A's sales department. Therefore, in the electrical department's design phase, the output of BOM data takes precedence over the creation of schematic diagrams. To better align with production, engineers will first create layout diagrams (or arrangement diagrams) based on equipment model data. This way, when engineers design the schematic diagrams later, the workshop engineers can first create the equipment layout. After the wiring schematic is designed, the design BOM is refined based on the design content (adding commonly used equipment such as lights and buttons), the layout diagram is improved, and the wiring diagram is generated.
2) Closed loop of design and inspection
The lack of design rule checks can render designs impractical and unrealistic. Electrical design requires a robust check mechanism. In elecworks, this mechanism is divided into two types: internal logical checks and external report checks.
Internal logical judgment:
Through data interaction, various parameters form an invisible data flow platform at each design stage. Design rules need to be established and integrated into this data flow platform. For example, regarding the uniqueness check of equipment labels, the uniqueness range of labels can be set in the project configuration before starting an engineering design. As shown in Figure 3, the uniqueness range of equipment labels needs to be defined before the project begins. If the uniqueness range is selected as "Project", then no duplicate equipment names are allowed in the entire project. This rule is effective for a single device; if a project has two devices, then the range of this rule needs to be changed according to the design requirements.
Figure 3 defines the uniqueness of the annotation.
In addition, there are line type definition rules, document page numbering rules, annotation numbering rules, etc.
These inherent rules fall under the category of "corporate standardization," and establishing sound design rules can effectively prevent mistakes.
External report inspection:
Simple standardized rules are insufficient for comparing design results. A more in-depth assessment of the design outcomes requires the use of elecworks' "Drawing Rules Check".
To be precise, it's not the software that "judges," but rather the software that provides the necessary data for designers to make their judgments.
As shown in Figure 4, the software provides a manager for error checking, which contains a large number of design rule error checking templates. Engineers can select the appropriate template as needed (for example, the slot fill rate check can extract and display the saturation of the slots), reducing the impact on the correctness and effectiveness of the design results.
Figure 4. Drawing rule check
By establishing internal and external mechanisms, a closed loop of design and inspection is formed, ensuring the accuracy of the design—this provides an effective data source for the integration of PDF systems.
3) Modular and parametric design process
Based on libraries, engineers can reuse data resources. In fact, different functional modules can also be distinguished in the design of schematic diagrams. Company A mentioned above adopted the concept of modules and used elecworks' "functions" to manage the system design content (as shown in Figure 5).
Figure 5 shows the drawings managed according to functional modules.
Based on the modular design, the data within the modules is parameterized, so that the final materials can also be managed according to this function (as shown in Figure 6).
Figure 6. Materials managed according to functional modules
After a year, Company A has accumulated a large number of modules and has now entered the "optional" design mode, as shown in Figure 7.
Figure 7 Optional Design Pattern
Based on order requirements, simply select the modules to be configured, and elecworks will automatically generate the module's drawings and reports, making the design process much simpler.
With graphics and parameters provided during the design phase, the PDM system can effectively manage the design process.
2. Information integration based on PTCWindchill
1) System Architecture
Traditionally, PDM systems only manage the design results, that is, the drawings uploaded by designers to the PDM system. PTCWindchill adopted a different approach when managing engineering data from elecworks. The complete system architecture is shown in Figure 8.
Figure 8 System Integration Business Process Diagram
PTCWindchill needs to manage data from the entire product design process, so electrical design drawings and equipment BOMs need to be entered into the system.
2) Management of material data
The creation of materials must be initiated by the PDM system and pushed to elecworks to avoid human intervention by engineers.
When creating push rules, the SQL fields of elecworks can be directly accessed by Windchill. Some variable descriptions are shown in Table 1.
Table 1 Variable Description Table
During the material check-in process, since material information exists simultaneously in both the PDM system and the elecworks client, the check-in interface automatically compares the material information to determine if the local material data matches the data in the PDM system. If they do not match, the check-in is denied, and an error message is displayed. If they match perfectly, Windchill automatically creates the corresponding structure tree based on the elecworks BOM structure, as shown in Figure 9.
Figure 9. BOM structure tree in Windchill
3) Management of electrical documents
The check-in/check-out of electrical engineering documents enables version control of the project. The approval and browsing processes require drawings to be generated in PDF format, and procurement requires materials in Excel format, as shown in Figure 10. — All of this needs to be automatically completed by elecworks during project check-in/check-out, avoiding manual intervention by engineers.
Figure 10 Project document in Windchill
4) Management of process documents
Mechanical design is a separate process, and the PDM system has its own independent workflow and management system for managing mechanical design, which will not be elaborated here. Mechatronics design requires that electrical data can be associated with the mechanical model to form a closed-loop design of 2D principle - 3D layout - automatic wiring - 2D report. In this way, a wiring process table with wiring length can be generated (as shown in Figure 11) and checked into the system.
Figure 11 Wiring process table including wire length
5) Management of design changes
When a design change occurs, the engineer checks out the engineering design data, makes the modifications, and then checks it back into the project. Windchill automatically creates a new version of the data. If materials change, Windchill can automatically compare the material changes between different versions.
IV. Conclusion
By using elecworks and PTCWindchill to jointly build an electrical information platform for the enterprise, the design process and output process were optimized, standardized design and management were achieved, the degree of human intervention was reduced, data could freely interact in the information platform, and the security and reliability of information were ensured.
