This topic describes the model quality check module of the product carbon footprint, including model quality check and mass balance check. The model quality check module identifies issues related to model integrity and offers suggestions for model optimization.
Model quality check
After the model is created, click Calculate and Publish. The system automatically checks the model quality before carbon footprint calculation. You can also click Model quality check, and the system checks only the model quality without calculating the carbon footprint. The model quality check module identifies issues related to model integrity and offers suggestions for model optimization.
You must fix all the model integrity issues before the system can calculate the carbon footprint. Click Complete the Data to go back to the model editing page. You must fix the integrity issues one by one.
Model optimization suggestions are optional and do not affect carbon footprint calculation. You can determine whether to optimize the model based on the suggestions.
Mass balance check
The mass balance check module checks whether the product carbon footprint model has mass balance issues.
Take note of the following items when you use the mass balance check module:
1. Deviation calculation: Deviation = [1 - (Output + Product)/Input] × 100%. If the deviation is 0, no mass balance issue exists. A deviation greater than 0 indicates that the mass of the input exceeds that of the product and output. A deviation smaller than 0 indicates that the mass of the input is smaller than that of the product and output.
2. You can click + to show each process. Then, you can change the value of the Correction Coefficient parameter and specify whether the inputs, outputs, and products are included in the mass balance calculation. You can also specify their quantities to be factored into the calculation. After you modify the correction coefficient, click calculate again. The system recalculates the mass balance deviation based on the latest calculation scheme. For example, if the quantity of an input item is 10 pieces and the correction coefficient is 2, the adjusted input quantity for the mass balance calculation is 20 kg (10 × 2).
3. The mass balance check module verifies the mass balance for both individual processes and the overall production process. The balance status of the overall production process is displayed in Raw materials acquisition and production stages in the first line.
4. The system provides default mass balance calculation schemes for both individual processes and the overall production process. (1) For individual processes, the inputs include raw materials, packaging materials, and products from other processes, the outputs include solid wastes, and the products are the products and by-products of each process. (2) For the overall production process, the inputs include raw materials and packaging materials, the outputs include solid wastes, and the product is represented by the total product yield (net weight). By default, the specified inputs, outputs, and products are automatically included in the calculation only if their mass units are specified. If the mass units are not specified, you must manually modify the correction coefficient.