11 - QUANTITIES AND PRODUCTIVITY OBJECTIVE Once the resource structure of the Matrix is substantially complete, begin entering the quantities and productivity information required to calculate the estimate. The recommended method is to work by Resource Type instead of trying to complete each item from top to bottom in a single pass. Working by specialty simplifies the review process, improves consistency, and makes it easier to detect omissions or unusual values. RECOMMENDED PROCEDURE Inside the Matrix sheet: 1. Confirm that the required resources have already been incorporated. 2. Filter the Matrix by Resource Type. 3. Begin with Materials. 4. Continue with Equipment. 5. Continue with Labor. 6. Review Subcontracts separately when applicable. 7. Finally, establish productivity and duration values. This sequence allows the estimator to concentrate on one type of resource at a time. MATERIALS Begin by entering the material quantities required for each item. Verify: • Correct unit. • Correct quantity. • Relationship between the resource quantity and the item quantity. • Possible waste or consumption factors when applicable. • Whether the material is supplied directly, purchased, or included in another resource. At this stage, the principal objective is to obtain realistic physical quantities. EQUIPMENT Continue with the equipment required to execute the work. Review: • Number of units required. • Hours per day. • Number of working days. • Equipment operating time. • Whether the equipment is owned or rented. • Whether transportation or mobilization should be considered separately. In ZUCOST, equipment usage can be calculated in hours from the quantity of equipment, working hours per day, and duration. LABOR After Materials and Equipment, review Labor. For each labor resource, consider: • Crew composition. • Number of workers. • Hours per day. • Productivity. • Duration. • Total labor hours. The purpose is to model the real labor effort required to execute the item. PRODUCTIVITY Productivity is one of the most important variables in an estimate. ZUCOST allows productivity to be analyzed using related values such as: • Unit/Day. • Min/Unit. • Days. • Hr/Day. • MH. These values should represent a realistic execution rate based on: • Historical performance. • Field experience. • Construction method. • Crew composition. • Site conditions. • Access limitations. • Weather conditions. • Learning curve. • Work restrictions. USE ONE PRODUCTIVITY APPROACH CONSISTENTLY When estimating productivity, avoid entering contradictory assumptions. For example, if an item is expected to produce a certain number of units per day, the corresponding duration should be consistent with the item quantity. Likewise, if the estimator defines Minutes per Unit, the resulting Units per Day and duration should make technical sense. WORK BY RESOURCE TYPE Filtering by Resource Type is strongly recommended. Typical sequence: MATERIALS Enter and review physical consumption. EQUIPMENT Define quantities, operating hours, and duration. LABOR Define crew quantities and labor effort. SUBCONTRACTS Enter subcontract quantities and adopted costs when applicable. This method allows the estimator to compare similar resources across many items and detect inconsistent assumptions more easily. WHY THIS IS IMPORTANT Trying to complete every field of one item before moving to the next can make a large estimate difficult to control. Working by specialty provides several advantages: • Faster data entry. • Better comparison between similar resources. • Easier detection of abnormal quantities. • Better productivity consistency. • More efficient use of filters. • Reduced risk of omissions. • Faster technical review. REVIEW THE RESULTS After entering quantities and productivity values, review the calculated results. Look for: • Extremely high or low durations. • Unusual labor hours. • Equipment hours that do not correspond with duration. • Material quantities that appear disproportionate. • Items with missing quantities. • Resources with zero values that should contain data. IMPORTANT Do not use productivity values only because they were used in another project. Productivity should always be reviewed against the specific conditions of the current project. A reasonable cost depends not only on the resource price, but also on the amount of resource required to complete the work. RECOMMENDATION Complete quantities and productivity by Resource Type, not randomly. A disciplined sequence such as Materials → Equipment → Labor → Subcontracts → Productivity makes the Matrix easier to build, review, and correct. Once these values are complete, the estimate is ready for more detailed cost review and recalculation.