Material costs represent 60% or more of the total expenses in engineering projects, making them a critical focus for cost control. Engineering projects involve a wide variety and quantity of materials. To enhance management efficiency, these materials are classified following the Pareto principle. Originally, the Pareto principle observed that 20% of people hold 80% of the world’s wealth, while the remaining 80% possess only 20%. This concept has since been adapted as a management strategy across various fields.
Although steel bars, concrete, and masonry materials make up a small fraction of all material types, their usage during construction accounts for over 80% of total material costs. These three are categorized as Class A materials, indicating they are few in types but highly significant in usage. Other materials, like cement, gypsum, and sand, fall under Class B. Effective classification enables targeted management, saves time, and improves overall efficiency.
Delays in supplying Class A materials can significantly disrupt construction progress, causing work stoppages and delays that waste manpower and increase unnecessary costs. For critical materials like concrete, steel bars, and masonry, a supply chain procurement model is essential.
Effective supply chain management is key to controlling project costs, starting with careful supplier selection. Different projects have varying supplier requirements, so selections should align with the specific needs of the project. For example, due to the unique nature of commercial concrete, communication with suppliers is enhanced through the BIM collaborative platform. This allows suppliers to anticipate the types, quality, quantities, and delivery schedules required, ensuring timely supply and fostering a mutually beneficial partnership.
Steel bars require on-site processing after delivery. To maintain smooth construction progress, it is advisable to purchase steel bars in advance and maintain a reasonable inventory.
Class B materials, such as cement and sand, are used in large quantities over extended periods. Their transportation costs often exceed inventory costs, so maintaining a reasonable inventory is necessary. Other Class B materials like gypsum and glass have more types and lower utilization rates, making zero inventory management—common in manufacturing—more appropriate. Excess inventory not only occupies valuable site space and hinders construction but also ties up capital.
Using the BIM 4D model, project managers can determine the start time of upcoming processes, identify the specific materials needed, and create detailed demand plans. This supports selecting the right procurement method and purchasing the correct quantities and quality of materials at the optimal time.
Materials are tracked and managed through a distribution board. Guided by the material requirement plan, the distribution board is updated daily by a dedicated person to ensure accountability and prevent misuse or waste.
After project completion, it is crucial to analyze and evaluate cost management. Comparing actual costs against planned budgets helps identify the causes of any discrepancies.
During construction, existing BIM models provide essential information such as project quantities. Additionally, new information is continuously added to the model to reflect the real status of components, enhancing the model and supporting future operations and maintenance.
Cost analysis involves calculating deviations between actual components and model components, then identifying the reasons behind these differences. When deviations result from improper human actions, the responsible parties are held accountable. This process not only helps accumulate valuable experience and avoid similar issues in the future but also strengthens personnel responsibility, further refining cost management from a human perspective.
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