These are the questions from the textbook named “the planning and the analysis of construction operations”
Question [1]
A pallet truck picks up 35 brick pallets at the vendor’s location and transports them to the job site, where they are off-loaded and stockpiled as 35 individual units. Draw simple model for this situation utilizing the CONSOLIDATE and GENERATE functions to minimize the number of units flowing in the system. Locate a COUNTER so as to measure the production rate in pallets stockpiled at the job site.
Question [2]
There are four columns to be poured, all of which are 24 in. in diameter and 10-12 ft in height. Therefore, each column requires approximately 1-1.5 yd3 of concrete. Prior to placing concrete, the columns are formed with circular metal forms and scaffolding is assembled in position around each column form.
a. The crane lowers the concrete bucket (1-yd3 capacity) into position at the transit mix truck, where a laborer positions the chute so that the bucket may be filled. The truck operator (teamster) regulates the feeding of concrete into the bucket.
b. After the bucket is filled, the crane swings the bucket to a position over one of the columns, where it is positioned into place by two laborers working on the scaffolding.
c. Once the bucket is positioned the concrete is released and, after settling in the form, is vibrated by a third laborer working from the scaffolding.
d. After the bucket is emptied and a signal is given by one of the laborers on the scaffolding, the crane operator swings back to the transit mix truck whee the procedure begins anew, or the bucket is swung to another column if there is concrete remaining in the bucket.
Since each column will hold 1-1.5 yd3 of concrete, and the bucket holds only 1 yd3, each column will be visited twice by the bucket. If a pour on a column is complete and 0.5 yd3 remains in the bucket, the crane operator would move the bucket to the next column, the crew would reposition on the next scaffolding, and the remaining 0.5 yd3 would then be placed before the crane would return the bucket to the concrete truck for refilling. Identify the active and waiting states in the system described. How can the CONSOLIDATE function be utilized to implement the movement of the crew and the crane to the second column after 1.5 yd3 of concrete has been placed and vibrated? (Use a triggering sequence similar to that shown in Fig 7.8.)
Question [3]
A carpenter supervisor is in charge of a slab formwork erection crew consisting of three carpenter-laborer pairs. The supervisor instructs each work pair team on the sequencing and locating of forms, and inspects erected forms for stability and level. If faulty erection occurs, the supervisor assists in whatever corrective work tasks are required. If correct erection occurs, the supervisor indicates the location of the required next formwork section and monitors the other work pairs. Develop a control structure for the supervisor’s management assignment and incorporate probabilistic arcs to model the supervisor’s work sequence whenever faulty erection of formwork occurs. How would you establish the probabilities to be assigned to the probabilistic exit arcs?
