1. Problem Definition
The Small company applied to get subcontract works of moving sub-base material from the borrow pit to the site from the main contractor of road project.
2. Identify the Feasible Alternative
The subcontractor wants to determine the required production rate in order to estimate the required numbers and Types of Equipment to be used for moving sub-base material from borrow pit to site.
The subcontractor decided to use the productivity and Production equations to estimate the production rate and the required equipment.
Productivity = output/input
Productivity = Quantities/ work Hours
Production = Output/Time
3. Development of the Outcome for Alternative
The requirements of the main contractor are summarized in the below table:-
It is clear from Table-1 that the required equipment for this type of works are tipper truck and wheel loader (shovel).
Table -2 illustrates the productivity rates of the above mentioned equipment from the previous record of the subcontractor for similar projects.
4. Selection Criteria
In order to estimate the daily Production, the numbers of the required equipment the following steps should be followed;-
- The quantity of the daily and hourly sub-base material to be delivered to the site should be calculated.
- Productivity or production rate should be calculated based on the requirements of the main contractor and the daily and hourly sub-base material rate.
- Accurate Daily record and daily report should be registered to monitor the productivity of the equipment.
5. Analysis and Comparison of the Alternative
Tables 3-6 self-explanatory to the above mentioned steps
6. Selection of the Preferred Alternative
From table 3 the required daily Productivity is 4000 m3 and the hourly productivity is 400m3.
From table4 the hourly productivity of the tipper truck is 60 m3 that applies the required numbers of tipper trucks are (6.66) and this number should be rounded to next closest heights number so the numbers of trucks are 7 and the productivity changed to 57 as shown in table 6. Similar thing was done for the wheel loaders. The required numbers are (4.44) and rounded it to 5. And base on the change the productivity changed from 90m3to 80m3 as shown in table 6. Rounding the numbers of the equipment is a precautionary procedures to maintain the productivity in the event of the breakdown of any equipment.
Establishing trip sheet and daily productivity report is a great technique to control and manage the daily productivity.
7. Performance Monitoring and the Post Evaluation of Result
Productivity is one of the best way to estimate the required resources to be applied for the project therefore it is very important to understand the required scope of work to dedicate the required recourse for the project. Moreover the precise record from previous similar project is assist step to reach the right estimation but the updated changes in the norms and rate in the market should be taken in the consideration of the estimation.
- Consolidated Contractor Company, E. R. (2005). Construction Plant Handbook (2nd Ed.). Athena, Greece: Consolidated Contractor Company.
- Giammalvo, P. D. (1996). Formula you need to know. In Supplement Material (p. 25).
- Taha, R. A. (1998.). Construction management. In Management. Muscat, Oman: Sultan Qaboos University.