New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

Lectures 20 and 21

by: Nathaniel Bautz

Lectures 20 and 21 CEE 270

Nathaniel Bautz
GPA 2.9
System Analysis and Economic Civil Engineering
Bernd Schliemann

Almost Ready


These notes were just uploaded, and will be ready to view shortly.

Purchase these notes here, or revisit this page.

Either way, we'll remind you when they're ready :)

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

Here are the notes to Lectures 20 and 21
System Analysis and Economic Civil Engineering
Bernd Schliemann
Class Notes
25 ?




Popular in System Analysis and Economic Civil Engineering

Popular in Civil and Environmental Engineering

This 3 page Class Notes was uploaded by Nathaniel Bautz on Friday April 10, 2015. The Class Notes belongs to CEE 270 at University of Massachusetts taught by Bernd Schliemann in Spring2015. Since its upload, it has received 90 views. For similar materials see System Analysis and Economic Civil Engineering in Civil and Environmental Engineering at University of Massachusetts.

Similar to CEE 270 at UMass

Popular in Civil and Environmental Engineering


Reviews for Lectures 20 and 21


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 04/10/15
O 90 O 90 LECTURE 20 TRANSPORTATION AND TRANSSHIPMENT Transportation Problem gt A set of m sources from which a good is shipped Source i can supply at most si units gt A set of 11 destinations to which a good is shipped Destination j must receive at least dj units gt Each unit produced at source i and shipped to destination j incurs a unit cost of cij gt Objective is to satisfy the LP and minimize cost or maximize revenue Applications Transportation of goods Power distribution Water supply Production scheduling Work scheduling Distribution centers do not use The Prototype Example gt Three canneries produce canned peas supply gt Four warehouses receive peas from canneries demand gt Shipping cost per truckload between canneries and warehouse depends on distance labor costs and etc Notation gt m sources in row i where i 1 2 m gt 11 destinations in column j where j 1 2n gt cij cost per unit distributed gt u shadow price for supply constraint gt v shadow price for demand constraint Assumptions gt Requirements assumption fixed and balanced supply as well as demand gt Cost assumption total shipping cost is directly proportional to the number of units shipped gt Integer solutions assumption if si and dj are integers all basic variables will be integers Streamlined Simplex Steps gt 1 Initialization I Build transportation simplex tableau Find initial BF solution mn 1 using NW corner rule gt 2 Optimality Test I Basic cij ui vj Nonbasic cij ui vj 2 0 Iteration Select entering basic variable most negative I Determine leaving basic variable chain reaction I Determine new BF solution gt 4 Return to step 2 Transportation Issues VVVVVV V m O 90 gt Big M method gt Dummy source destination gt Basic variables can take on a value of 0 gt Degeneracy Transshipment Problem gt Shipments allowed between sources and destinations gt Distribution centers permitted transshipment points LECTURE 21 CRITICAL PATH METHOD 0 9 Projects amp Project Management gt Project goals I Complete on time or before I Not exceed budget I Meet specifications to customer satisfaction gt Define scope time frame resources gt Select the project manager team structure gt CPM PERT network or Gantt Chart Network Diagrams gt Precedent relationships determine the sequence for undertaking activities gt Activity times must be estimated using historical information statistical analysis learning curves or informed estimates gt In the activityonnode approach AON nodes represent activities and arcs represent the relationships between activities Develop a Project Network gt Iterative draft on scratch paper gt Keep writing out nodes and arcs gt Rearrange to remove intersecting arcs gt Don t forgot two special nodes I START I FINISH Scheduling Activities Forward Pass ES Earliest start time of an activity when there is no delay anywhere EF Earliest finish time of an activity when there is no delay anywhere d duration of an activity EF ES d Go forwards through the project network ES largest EF of immediate predecessors cheduling Activities Backward Pass LS Latest start time of an activity without delaying the project LF Latest finish time of an activity without delaying the project d duration of an activity LS LF d Go backwards through the project network WVVVVVV VVVVV gt LF smallest LS of immediate successors Slack gt A measure of how much an activity can be delayed without delaying the whole project gt SlackLS ES LF EF gt Slack 0 on the critical path Questions to be Answered gt Total time required to finish gt When to start and finish each activity gt Which are critical bottlenecks gt For other activities how much delay can be tolerated Crashing Activities gt Taking measures to reduce activity duration 39 Overtime I Temporary help 39 Special equipment I More costly materials e g finished lumber Marginal Analysis Iterative Method gt 1 Start from the critical paths gt 2 Pick an activity or a combination of activities with the lowest crash cost per week AND positive allowed reduction time that will reduce the length of the critical path by one week gt 3 Reduce each picked activity duration by one week gt 4 Reduce the allowed reduction time of each crashed activity by one week gt 5 Recalculate the critical path Go back to Step 2 gt 6 Stop when the desired project duration is reached For Multiple Critical Paths gt 1 Check activities on all critical paths gt 2 Find the least expensive way of shortening ALL critical paths by one week Note only when all critical paths are reduced by one week will the project duration be reduced by one week gt 3 Can crash one activity or a number of activities gt 4 Can be very complicated as the number of options can be large


Buy Material

Are you sure you want to buy this material for

25 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Steve Martinelli UC Los Angeles

"There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."

Allison Fischer University of Alabama

"I signed up to be an Elite Notetaker with 2 of my sorority sisters this semester. We just posted our notes weekly and were each making over $600 per month. I LOVE StudySoup!"

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."


"Their 'Elite Notetakers' are making over $1,200/month in sales by creating high quality content that helps their classmates in a time of need."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.