Small House Extension Project

Transcription

1 Small House Extension Project The activities of a small project are shown in the following network. Normal working hours are 8 hours/day. An overtime hour has %90 productivity of a regular hour. For the first overtime hours, hourly rate is.5 of a normal rate, afterwards it is twice the normal hourly rate. Select finishes Excavation Joining House House Interior Foundation wall walls roof finishes 5 7 Clean up 9 0 Garage walls Garage roof 8 Garage doors Fabricate garage doors. Estimating Exercise Let s take an activity and estimate its direct cost as a function of the resources used. Details of the basic resources, the working crew, and the two work options (normal work versus overtime) are: Labor: Code Description Rate/hr L General Laborer 5 L Concrete Worker 5 Equipment: Code Description Rate/hr E Crane & Bucket 50 E Pump & Tool 0 Crews: Code Description Unit Composition C Concrete Crew Cu ft L + L + E + E Materials: Code Description Unit Cost/Unit M Ready-mixed concrete Cu ft 7 Construction Options Description Unit Resources Production/day Concreting by Pump Normal work Cuft C + M 00 Concreting by Pump Overtime hrs Cuft C + M? Assume the activity is a concreting job to pour 500 cubic feet (Cuft) of concrete using pumps. We need to estimate the time and cost it takes to do the job using either the normal work strategy or the overtime strategy. We need to do this both manually and using EasyPlan. Also, estimate a reasonable daily indirect cost/day assuming supervisors rate is $5/hour. This exercise demonstrates that options we have either cheap and slow or fast but expensive strategy to conducting the work. Each option has its resource types and/or working hours. Accordingly, the time and cost may vary substantially. It is also clear that the essential data needed for detailed estimating is the production rates of the resources, which can be found in many references such as the Means.

2 . Scheduling Exercise Assume the activities durations are as shown below. Draw an AON representation of the project network. Manually calculate the project duration and determine the critical path. Use Microsoft Project software to enter the activities, their durations, and their logical relations. Save the file. Open EasyPlan, start a new project and import the Microsoft Project file you saved. Print the solutions of the manual calculations, Microsoft Project, and EasyPlan. Select finishes Excavation Foundation Joining wall House walls 5 House roof 7 Interior finishes 9 Clean up 0 Fabricate garage doors Garage walls Garage roof 8 Garage doors Legend: Activity Duration. Project Optimization Exercise Open EasyPlan, start a new project, enter the same activities of this example, and enter the following three estimates for each activity. Notice that the underlined numbers are the ones with different values: Activity Description Excavation Foundation Joining Wall House Walls House Roof Select Finishes Interior Finishes Clean Up Fab. Garage Doors Garage Walls Garage Roof Garage Doors Estimate Normal Work Estimate Overtime Estimate Weekends Dur. (d) Cost ($) Dur. (d) Cost ($) Dur. (d) Cost ($),000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000 0,000,000,000,000,000,000,000,000,000,000,000,000 Also, enter the following project information: Project deadline is days. Indirect cost is $00/day, penalty for late completion = $/day, incentive for early completion = $000/day. Each activity uses labors (L5) daily. Resource limits is - L5 resources per day. A reporting period is days and interest rate is % per period. Your Markup is 0% but owner retention is 5% of each invoice. For all activities, winter productivity = 0.7, spring =.0, and summer = 0.85.

3 a. Ignoring the deadline and using the first estimate of each activity, determine the planned project duration if the start date is either Aug., 00, Oct., 00, or Jan., 00? b. If project start date is May, 00, determine the optimum execution plan that meets the resource limits at minimum cost, ignoring the deadline duration (you may be able to friendly negotiate an extension). Activate EasyPlan optimization (more than once if necessary) and determine the activities start delays that avoid exceeding resource limits. c. If project start date is May, 00, determine the least-costly execution plan that meets the -day deadline, ignoring resource limits. Activate EasyPlan optimization (more than once if necessary) and determine the necessary work option to use in each activity. d. If project start date is May, 00, determine the optimum execution plan that meets both the deadline and resource limits at minimum cost. Activate EasyPlan optimization (more than once if necessary) and determine the necessary work option to use in each activity. e. Compare the three above plans and choose your best one.. Markup Estimation Exercise You anticipate that there will be bidders competing with you for that project. Three of the competitors are Company A, Company B, and Company C (included in the bidders list of EasyPlan. The fourth competitor is similar to Company B. Use EasyPlan to estimate a reasonable markup value for winning the competition at a fair profit. 5. Bid Unbalancing Exercise Before you can print a bid proposal, let s look at the financing charges that apply to this project. From EasyPlan reports, look at the Cash Flow report and take note of the interest charges. Print the balanced prices for the project activities. Then, let s use the Optimization feature to see if we can reduce the interest charges without reducing the total bid value. Print the unbalanced prices for the activities.. Site Layout Exercise Congratulations. You have won the bid and have officially been handed the site. According to the site size is 50 ft x 50 ft. The site can be drawn using cells each 0 ft x 0 ft (5 x 5 cells). The building to be built and some restricted areas are shown on the site plan. Also, there exists on site a small storage area (Facility ) on a fixed location on the site. We are now interested in placing three new facilities: =Batch Plant, =Site offices, and =Workshop. The project manager has the following preferences: Facility with fixed location on site. - Batch plant very far from all other facilities; - Workshop very close to storage area; & - Site offices far from storage & workshop. a) Use EasyPlan to determine the optimum site layout for the project. b) With the best layout, we need now to put a crane as close as possible to the center of the building, and all other facilities on site except the site offices. Temporary Facility to b e placed on any site location by writing its number in any cell. Obstacle or unallocatable place on site.

4 7. Project Control Exercise Before entering actual progress, let s first save the project plan as a baseline for progress evaluation. During actual progress, the following events were encountered during the first days of the project: During Excavation, the contractor completed 0% during the first day, then encountered unexpected rock at the beginning of day. Accordingly, Excavation was stopped for days until a new machine is procured. Afterwards, Excavation resumed and the contractor completed the remaining work on two days. The Foundation and the Joining Walls activities were completed with their durations being as planned. After two days of working on the House Walls, the owner stopped the contractor for two days to complete some changes in the windows design. The contractor s framing subcontractor abandoned the job after working days on the House and Garage Walls. It took days from the contractor to get a new framer. The contractor started the Order Garage Doors on day but the owner did not have time to Select the Finishes. Actual costs are almost 50% more than planned. a. What is the expected project duration and cost in light of these events? b. What is your optimum corrective action plan? Starting day, actual progress continued as follows: The owner didn t start on Selecting Finishes until day 9. The contractor took days longer than planned to complete the interior finishes. The contractor took day longer than planned to complete the Garage Walls. The House Roof and the Garage Roof activities took no longer than their planned durations. Garage doors arrived on site at the end of day 7but the owner changed his mind and requested different doors. It took days to get the new doors. c. Plot the project S-Curve and Earned-Value curve. d. Print the payment schedule, Cash Flow chart, and the resource histograms. e. Print your final as-built schedule. Do you recommend the contractor to submit a request for time extension? f. Experiment with contractor versus owner acceleration on delay analysis results.

5 Sample Solutions. Project Initiation Starting a new project from the PROJECT menu, as shown. On the Main Screen, input the general data for the project such as: start date, working days, name and limit of three key resources, project deadline ( days), etc. For the Indirect Cost, you may enter an estimate for daily indirect cost directly ($00) or click on the red button to enter the details of indirect costs. This a list of animations that show all EasyPlan unique features. It serves as a simple tutorial. A good place to start. Also, for the Mark Up, the user may enter an estimate percentage for the mark up directly (0 %) as shown in the Main Screen or by clicking on the blue button, you proceed to the powerful bid analysis module of EasyPlan.. Activities and Estimate Data of the present case study To specify the project activities and their three optional estimates, proceed to the Project menu then Activities and Estimates option. You can add or delete an activity using the buttons shown. One option is to manually enter the costs and durations for the three work options, in addition to the seasonal productivity factors and resource amounts. Note that adding/deleting activities is enabled only before actual progress is entered, therefore, it is wise to add a couple of extra activities just in case. 5

6 Another option is to use the Auto Estimates feature and EasyPlan will automatically calculate the activities costs and durations based on the user inputs of information related to the labors, equipment, materials, etc. By clicking the Edit button on the first estimate of activity Excavation, you can edit the estimate details as shown. While defining the estimate details, you may define crews, materials, seasonal productivity factors, etc. To add/delete crews, for example, click on the Edit button next to the crew name. A form for defining crews will pop up as shown. Note: Before estimating begins, you may store all your available labour, equipment, materials, crews, and subcontracts in EasyPlan s Resource Bank.. Schedule Details Let s consider the three manual estimates shown in the previous page, and also consider that the labour (L5) category is considered as a key resource that has a daily limit of units (inputs in the Main Screen). Now, view the schedule by selecting the Project then CPM and Schedule Details option. You may view and change the CPM logic by choosing the More button (not shown in this screen). Once done, voila project duration is days.

7 You may now return to Main Screen to see if resource limit is exceeded. You will notice that we exceed the deadline by two days and also we need to use six of the L5 resource i.e., two more than available. How does EasyPlan help you resolve this issue?. Schedule Optimization From EasyPlan toolbar, choose Project then Optimize Schedule option. From this screen, we can set the constraints and the optimization parameters as shown, then Proceed. The optimized schedule came up with the following results: a. of L5 are used, respecting the daily limit. b. Project duration = days = deadline duration. c. Total project cost of $9,00 which is much less than initial. Optimum start delays Optimum work option After obtaining the optimized schedule that meets the project deadline and satisfies the resource constraints, you may save this schedule as baseline.. Project Progress and Updates Now, let s start entering the actual progress as described in this example, for the first days. Accordingly, the actual progress vs the base line bar chart appears as shown in the following figure. 7

8 You can enter actual data using three ways: - Directly enter values in the actual bar cells; - Click on the [<] button next to any actual cell to edit its data; or - Click on the new daily events button to enter the events of one day at a time. Now, continue entering actual data as per the description given in this project for the first days. The updated schedule is shown here with projected completion date of days. Using this bar chart, we are able to record the actual progress as a daily percentage. Also, reasons for delays are recorded as a comment on the cell, as shown in the figure. Note: The project completion date is 7-days longer than the project baseline duration. A corrective action is needed to shorten the project duration. Accordingly, we will run the optimization process again in order to optimize the remaining pat of the project. 8

9 By running the optimization, the remaining part of the project has been adjusted and the projected completion became 8 days (shorter by -days than the previous one). It is noted that if we really need to meet the strict -day deadline, we may go back and change the estimate options of some activities to reflect new technology, more productive equipment, or more experienced crew to recruit. Then, we re-optimize the project using these better project options. In the next step, we continue entering the remaining activities progress. As we can see from the following figure, the project completion time is days. Now you can activate the delay analysis option to analyze progress and determine the responsibility of this delay. As-Built versus As-Planned Project Schedules 9