Critical Path Analysis, EST, LST, EFT, LFT & Project Network

Project management

1. A re-finisher of antiques has been very successful with her small business and is planning to expand her
shop. She is going to expand by purchasing the larger equipment as shown below. Determine a cost for
the business owner using the cost index and sizing data for each piece of equipment purchased. Assume
that there is a 15% trade-in allowance for the old equipment based on the original cost.
New size Cost
Cost index
Cost index
Varnish bath $3500 50 gal 75 gal 0.8 154 171
Power scraper $250 ¾ hp 2.0 hp 0.22 780 900
Paint booth $3000 3 ft3 15 ft3 0.6 49 76
2. A heat ex-changer cost $7500 in 2005 and must be replaced soon with a larger unit. The present unit has
an effective area of 250 feet and its replacement should have an area of 350 feet. Replacement is
anticipated in 2015 when the price index is estimated to be 170 where it was 115 when the ex-changer
was first purchased. Estimate the cost today if the cost capacity factor is 0.6.
3. Develop an estimate for the cost of washing a load of dishes in an automatic dish washer. Remember to
consider all the costs.
4. The Schuman Company is considering the construction of a ski lodge and ski complex. The board of
directors has voted to build a 10 million dollar complex. Stage one of the complex will be constructed in
year 1 and will include the construction of a day lodge, chair lift, rope tow, generator house (for
electricity) and a parking lot designed to accommodate 400 cars and 30 buses. Stage one will begin no
later than April 1 and should be completed by October 1 in time for the next ski season. You have been
assigned as project manager. You and your team has researched the tasks and duration and have
determined the following time estimates. Materials for the chair lift and rope tow will take 30 days and
12 days respectively to arrive once the order has been submitted. Lumber for the day lodge, generator
hut, and foundations will take 9 days to arrive. The electrical and plumbing materials for the lodge will
take 12 days to arrive. The generator will take 12 days to arrive. Be for actual construction can begin, a
road to the site must be build which will take 6 days. As soon as the road is in, clearing can begin
concurrently on the sites of the day lodge, generator house, chair lift and rope tow. It is estimated that
the clearing task at each site will take 6 days, 3 days, 36 days and 6 days respectively. The clearing of
the main ski slopes can begin after the area for the chair lift has been cleared and will take 84 days. The
foundations for the day lodge will take 12 days and construction of the main framework will take an
additional 18 days. After the framework is completed, electrical wiring and plumbing can be installed
concurrently. These should take 24 and 30 days, respectively. Finally, the finishing construction on the
day lodge can begin; this will take 36 days. Installation of the chair lift towers (67 days) can begin once
the site is cleared, lumber delivered, and the foundation completed (6 days). Also, when the chair lift
site has been cleared, construction of a permanent road to the upper towers can be started; this will
take 24 days. While the towers are being installed, the electric motor to drive the chair lift can be
installed; the motor can be installed in 24 days. Once the towers are completed and the motor installed,
it will take 3 days to install the cable and an additional 12 days to install the chairs. Installation of the
towers for the rope tow can begin once the site is cleared and the foundation is build and poured; it
takes 4 days to build the foundation, pour the concrete and let it cure, and 20 days to install the towers
for the rope tow. While the towers are being erected, installation of the electric motor to drive the rope
tow can begin; this activity will take 24 days. After the towers and motor are installed, the rope tow can
be strung in 1 day. The parking lot can be cleared once the rope tow in finished; this task will take 18
days. The foundation for the generator house can begin at the same time as the foundation for the
lodge; this will take 6 days. The main framework for the generator house can begin once the foundation
is completed; framing will take 12 days. After the house if framed, the diesel generator can be installed
in 18 days. Finishing the construction on the generator house can now begin and will take 12 more
a. Draw the network diagram
b. Determine the project length
c. Determine the EST, LST, EFT, LFT for the project tasks
d. Determine the critical path and the slack for each task.
e. Can the project be completed by Oct 1? Explain.