Construction Scheduling and Estimating

Someone gets an IDEA The IDEA inspires a PLAN to be created The PLAN is used to build the

SCHEDULE The SCHEDULE drives the project.

IDEA: I want an “A” in a class.

PLAN: Study and do the work.

SCHEDULE: 1 hour outside of class will be spent

reviewing the lecture each day we have class.

Constraints – things that limit the project Equipment, labor, jobsite, time, money,

material, etc Critical Path – the activities that cannot

be delayed before preventing the project from finishing on time

Work Days vs. Calendar Days Work Days – days that workers will be working Calendar Days – days as they appear on a

calendar, including weekends and holidays

Duration – the amount of time spent on an activity; can be any time unit, but is normally days

Lag – time between one activity finishing and the next starting

Unexpected delays – a delay to the project that could NOT be reasonably anticipated by the contractor. Rain in May does not constitute an unexpected delay unless you can document that it is significantly more than you could have reasonably expected.

A small room needs to be painted. Name the type of constraint.1. 3 painters. 1 brush. 3 days. 3 gallon buckets of paint.

2. 1 painter. 3 brushes. 3 days. 3 gallons buckets of paint.

3. 3 painters. 3 brushes. 3 hours. 3 gallon buckets of paint.

4. 3 painters. 3 brushes. 3 days. 1 3-gallon bucket of paint.

5. 3 painters. 3 brushes. 3 days. 3 gallon buckets of paint.

Equipment constraint - only 1 brush

Crew constrained – only 1 painter

Time constrained – only 3 hours

Material/crowding constrained – lower productivity because sharing a bucket

Productivity constrained – only as fast as workers can go

What does each constraint mean?1. Assuming a separate crew dedicated to service road construction from turbine construction. 2. Only 1 crew for turbine construction, but can perform all activities except road work. 3. All equipment is available as needed, but may only mobilize once per turbine site. 4. Concrete footings will need to set for 7 days before any work can be done on top of them. 5. It takes 5 days per site for service road construction. 6. No weekend time should be accounted for. 7. Create a schedule for these activities using the durations given. 8. Fill in the boxes for when the activities occur.

What does each constraint mean?1. Service road construction and turbine construction can occur at the same time if necessary.2. Only 1 crew for turbine construction, but can perform all activities except road work. 3. All equipment is available as needed, but may only mobilize once per turbine site. 4. Concrete footings will need to set for 7 days before any work can be done on top of them. 5. It takes 5 days per site for service road construction. 6. No weekend time should be accounted for. 7. Create a schedule for these activities using the durations given. 8. Fill in the boxes for when the activities occur.

What does each constraint mean?1. Service road construction and turbine construction can occur at the same time if necessary.2. Work can only be done on one jobsite at a time, because a crew works together and does not split where they are working.3. All equipment is available as needed, but may only mobilize once per turbine site. 4. Concrete footings will need to set for 7 days before any work can be done on top of them. 5. It takes 5 days per site for service road construction. 6. No weekend time should be accounted for. 7. Create a schedule for these activities using the durations given. 8. Fill in the boxes for when the activities occur.

What does each constraint mean?1. Service road construction and turbine construction can occur at the same time if necessary.2. Work can only be done on one jobsite at a time, because a crew works together and does not split where they are working.3. You do not need to wait for equipment, but you must finish work at one site before moving onto the next site.4. Concrete footings will need to set for 7 days before any work can be done on top of them. 5. It takes 5 days per site for service road construction. 6. No weekend time should be accounted for. 7. Create a schedule for these activities using the durations given. 8. Fill in the boxes for when the activities occur.

What does each constraint mean?1. Service road construction and turbine construction can occur at the same time if necessary.2. Work can only be done on one jobsite at a time, because a crew works together and does not split where they are working.3. You do not need to wait for equipment, but you must finish work at one site before moving onto the next site.4. The lag value on concrete indicates the amount of time the concrete has to cure before it is strong enough to work on.5. It takes 5 days per site for service road construction. 6. No weekend time should be accounted for. 7. Create a schedule for these activities using the durations given. 8. Fill in the boxes for when the activities occur.

What does each constraint mean?1. Service road construction and turbine construction can occur at the same time if necessary.2. Work can only be done on one jobsite at a time, because a crew works together and does not split where they are working.3. You do not need to wait for equipment, but you must finish work at one site before moving onto the next site.4. The lag value on concrete indicates the amount of time the concrete has to cure before it is strong enough to work on.5. The total duration of road construction is 10 days, but the road to the first site will be completed in 5 days. 6. No weekend time should be accounted for. 7. Create a schedule for these activities using the durations given. 8. Fill in the boxes for when the activities occur.

What does each constraint mean?1. Service road construction and turbine construction can occur at the same time if necessary.2. Work can only be done on one jobsite at a time, because a crew works together and does not split where they are working.3. You do not need to wait for equipment, but you must finish work at one site before moving onto the next site.4. The lag value on concrete indicates the amount of time the concrete has to cure before it is strong enough to work on.5. The total duration of road construction is 10 days, but the road to the first site will be completed in 5 days. 6. Only schedule work to be done Monday through Friday.7. Create a schedule for these activities using the durations given. 8. Fill in the boxes for when the activities occur.

What does each constraint mean?1. Service road construction and turbine construction can occur at the same time if necessary.2. Work can only be done on one jobsite at a time, because a crew works together and does not split where they are working.3. You do not need to wait for equipment, but you must finish work at one site before moving onto the next site.4. The lag value on concrete indicates the amount of time the concrete has to cure before it is strong enough to work on.5. The total duration of road construction is 10 days, but the road to the first site will be completed in 5 days. 6. Only schedule work to be done Monday through Friday.7. Create a schedule for these activities using the durations given. 8. Fill in the boxes for when the activities occur.

Nothing can be done until the service roads are built. On the solution, red will indicate the critical path, and green will indicate activities that are NOT on the critical path. The first week is dedicated to the construction of the road for the first site. After the first road is done, the construction activities at the first site can begin, while the second road is being built simultaneously.

The service road to the second site is NOT on the critical path because work on the second site does not begin until after the first site is completely finished (day 29). This means that even if the road to the second site was done a day late, it would not impact the finish date of the project. As long as it is completed BEFORE the work is to start on the second site, it will not matter when it is done. Regardless, it should still be on the schedule as early as possible to demonstrate when it CAN be done.

Activity 5, the pouring of the concrete footing is completed on day 15, but the seven days of lag value have to finish before the next activity can start. It does not matter that it is over a weekend, because no workers are actually doing anything while the concrete is curing. So, no work is done on the jobsite between day 16 and 22. Once the lag time is over, the next activity can be done, in this case on day 23. The next five activities occur one after another in the next 3 days.

The rest of the schedule follows the model of the first turbine, with one activity following the previous one. The total duration of the project is 60 days with this schedule. This schedule is constrained primarily by the single crew.

What is different in Problem #2?Assuming a separate crew dedicated to service roads construction from turbine construction. 1 crew available for EACH turbine construction, and can perform all activities except road work. All equipment is available when needed, with each site having its own dedicated equipment. Concrete footings will need to set for 7 days before any work can be done on top of them. It takes 5 days per site for service road construction. Work on the second site can't start until the service roads are completed to it. No weekend time should be accounted for. Create a schedule for these activities using the durations given. Fill in the boxes for when the activities occur.

This means that work on BOTH turbines can occur simultaneously. However, it does STILL need to wait for its service road to be completed. Both activities will need to be inspected at the same time. Because of the delay to the start of the second turbine, it becomes the critical path. All of the work on the first turbine can be delayed by a couple of days before it falls onto the critical path. Because there are crews and equipment for each site, the total duration of the project is dropped to 45 days from 60.

What is different in Problem #3?Assuming a separate crew dedicated to service roads construction from turbine construction. 1 crew available for EACH turbine construction, and can perform all activities except road work. There is only 1 crane available, and it is only available for one week, Monday through Friday. However, because of the site locations, the crane can perform the same activity at each site on the same day(s). Concrete footings will need to set for 7 days before any work can be done on top of them. It takes 4 days per site for service road construction. Work on the second site can't start until the service roads are completed to it. No weekend time should be accounted for. Create a schedule for these activities using the durations given. Fill in the boxes for when the activities occur.

This problem is equipment constrained. The way to approach this problem is to work the problem until you are able to see when the crane will be needed. The tips and thoughts indicate which activities require a crane, and we know that these can and need to be done during ONE week, Monday through Friday. The schedule indicates that the job will be READY for the crane on day 26. The job is delayed until the following Monday to accommodate the requirement of the crane.

Because there is the one day delay before the crane is required, EVERY activity is non-critical. If, however, any activity is delayed by a single day, the following activities BECOME critical, because they will impact the completion date. If the activities are delayed by 2 days, the project becomes SIGNIFICANTLY delayed because the crane has to wait until the following week to show up on the job.

The description indicates that the crane can perform the same activity on both sites on the same day, so they are aligned accordingly. The project is completed with a total duration of 44 days with these constraints.

Assuming a separate crew dedicated to service roads construction from turbine construction.

1 crew available for EACH turbine construction, and can perform all activities except road work.

All equipment is available when needed, with each site having its own dedicated equipment.

Concrete footings will need to set for 7 days before any work can be done on top of them.

It takes 5 days per site for service road construction. Work on the second site can't start until the service roads are

completed to it. The owner is desperate for this project to finish and is willing to pay a

$200,000 bonus if you finish before day 38. Create most profitable schedule. Assume a box filled in (worked) on a weekend day costs $20,000 per

box. Create a schedule for these activities using the durations given. Fill in

the boxes for when the activities occur.

This problem has the exact same description as Problem #2, but this one has the possible financial bonus for early completion.

1. First, it is important to determine IF accelerating the schedule will be profitable.

2. To do this, we must determine which day the project would be completed without acceleration.

3. Looking back at Problem #2, we can see that the original completion date is day 45.

4. The bonus is contingent on the project completing by day 37. 5. Because a weekend can be counted as well, 6 days need to be

cut out of the schedule to be done BEFORE day 38. 6. Six days means 3 weekends worked. 7. Taking the price of $20,000 a day, the price of the overtime is

$120,000. 8. If a schedule is created in this manner, an additionally $80,000

can be made on the project.

Which weekends do you work the overtime?DO NOT work overtime for things NOT on the critical path. By accelerating the activities ON the critical path, the duration of the project can be shortened. Shortening non-critical activities does not affect the completion date.If it can be done, force the lag values to occur over as many weekends as possible. For this example, the seven day lag will occur over one and only one weekend.

As you can see, 6 weekend days are worked. Days 6 & 7, 13 & 14, and 27 and 34. Note that non-critical activities do not occur on weekends.

Every project will have different constraints. One constraint may seem to be dictating the project, but if something happens, a different constraint could cause other activities to fall onto the critical path. The most important thing to the duration of a project is the critical path. This is why scheduling can become complicated and is important. In practice, many constraints will exist, and it is important to determine which constraints are the most important and how they affect the project as a whole.

Watch video http://vimeo.com/28823577 Password:  isuW1nd