Construction Plan Comparison
Primary Plan
In our primary plan, we focused on efficiency and cost in our methodology. This plan’s excavation pattern starts at the south west corner of the site and work progresses toward the east end of the site. The site is broken up into strips running north and south and one strip is graded at a time working across the site. The first figure visualizes the progress of this plan throughout the project, showing roughly the work completed each week. The second figure is the breakdown of the schedule for this plan and shows which nodes will be completed on which days. Work days were scheduled at 9 hours with one hour for lunch, and approximately half an hour for daily set up and clean up.
The crew associated with this plan consists of 1 dozer and 1 excavator, 16 trucks, and 5 helpers, which includes the foreman. Throughout the project different concerns need to be addressed:
- Week 1 and 2 the major concern is the long haul distances and the interaction with the public at the site access point. Two helpers will be stationed at the site entrance as traffic control to ensure the safety of both the workers and the public.
- Week 3 there are some instances where the dozer and excavator are working in the same 20mx20m node. This will require extra care and direction to ensure crew safety. To address this, one of the helpers will be taken from traffic control to be stationed onsite to help direct equipment movement.
- Week 4 the biggest concern becomes onsite storage of material. The majority of this project involves hauling material offsite, but during week 4 some material needs to be stored onsite before being replaced in a different node. The helper moved onsite during week 3 will be re-positioned for traffic control.
- Week 5 is when the walkway connecting the school buildings will be shifted. By the third day of this week the walkway can be moved onto the graded section of the project.
- Week 6 is the last week of the project and will begin the demobilization and site clean up. The original crew will work on clean up, and to avoid overworking an additional helper will be hired to facilitate demobilization.
For this project, the engineering/planning is fairly straightforward, so we anticipate it to not require much in the way of expenses. Our company follows a standard formats for adding OH&P, as well as estimating the insurance, permits and sureties required to complete the job.
For this particular plan, we have values our Indirect Costs as follows:
- Eng Fees - 5%
- Permits - 5%
- Surety - 5%
- OH&P - 10%
- Insurance - 10%
Which totals to be 35% of the Direct Cost.
Considering that our original plan is fairly safe (see Safety Summary), we are only adding a contingency of 5% on top of our total marked up price.
This project plan is valued at $874,121.58.
Alternative Plan
The alternative plan was developed using the north east edge of the site as access point. This provides a better access to the road and takes the equipment traffic away from the site offices and is safer for the crew as a result. Construction scheduling was completed used a zoning approach. The site was broken down into 4 different zones and each zone was graded in turn, shown in the image to the right. Figure 3 is the breakdown of the schedule for this plan and shows which nodes will be completed on which days. Work days were scheduled the same as the primary plan at 9 hours with one hour for lunch, and approximately half an hour for daily set up and clean up.
The crew associated with this plan consists of 1 dozer and 1 excavator, 17 trucks and 5 helpers, which includes the foreman. To achieve a more cost-efficient production rate an additional truck was required compared to the primary plan.
The following is the approximate number of days each zone is scheduled to take:
Zone 1 - 9 Days
Zone 2 - 5 Days
Zone 3 - 3 Days
Zone 4 - 11 Days
By using zoning in the alternative plan the construction activities are more limited onsite, making a safer work environment for the crew.
For this project, the engineering/planning is much more difficult, so it is in our best interest to increase the estimation of fees associated with the project
For this particular plan, we have values our Indirect Costs as follows:
- Eng Fees - 10%
- Permits - 5%
- Surety - 5%
- OH&P - 10%
- Insurance - 10%
Which totals to be 40% of the Direct Cost.
Considering that this plan is more risky (much more frequent interaction with the school border throughout the project), we added a contingency of 10% on top of our total marked up price.
This project plan is valued at $907,198.25 and is not being recommended. We are showing it here for comparative purposes.
Our Recommendation
Cost Comparison
The chart above compares the weekly and cumulative project costs for both construction plans. Due to it's complexity and larger crew, the alternative plan is consistently more expensive.
Earthwork Comparison
The chart above compares the weekly and cumulative earthwork volumes for both construction plans. Both plans have fairly consistent volumes of earthwork, but the alternative plan has significantly less volume in the last week.
Due the significantly increased complexity associated with the alternative plan we recommend the original plan.
The simplicity of the progression onsite in the original plan reduced engineering costs, and the design allowed the same 6-week schedule with a smaller crew. These together made the original plan become significantly cheaper than the alternative.
The original plan also has much less risk involved. The straightforward advance onsite is easier to track and execute. The schedule of the alternative plan may be harder to execute due to the need to relocate to the next zone.
The alternative plan does involve slightly less total earthwork. Since the sequence the grading of the nodes is not restricted to the linear progression, less material had to be stored onsite. This is because material could be brought directly from cut nodes to fill nodes without storing it first.
Ultimately we recommend the original plan because it is cheaper, simpler, and has less risk involved.