Showing posts with label Engineering Economics. Show all posts
Showing posts with label Engineering Economics. Show all posts

Selection of Motor - A Design Engineer's Problem - Engineering Economic Analysis

A design engineer has to select a 100 hp motor for a plant that operates 2000 hours in year. Model A-90 costs Rs.2,00,000 and has a full load efficiency of 89.5%. Model A-91 costs Rs.2,40,000 and has a full load efficiency of 91%.
 
Energy costs Rs. 2 per KWH. (0.746 KW = 1 hp).
 
The life of the motors are expected to be 12 years and the salvage value will be 5%. Which motor is to be specified by the design engineer?
Original Knol - http://knol.google.com/k/narayana-rao/selection-of-motor-a-design-engineer-s/2utb2lsm2k7a/ 598

Engineering Economics is an Efficiency Improvement Tool for Industrial Engineers

An Article to Note


The Role of IE in Engineering Economics.


By Riel, Philippe F.
IIE Solutions, April 1998


Industrial engineering (IE) plays a significant role in engineering economics. IE promotes investment justification processes that determine the appropriateness and value of projects. It also supports investment analyses correlated with the overall corporate strategy. Moreover, IE advocates evaluation processes that advance interdisciplinary thinking among company employees who design cost models and evaluation frameworks that are utilized in decision support systems for a variety of technological projects.


______________________________________________________________

The idea that I advocate in this article is that the set of evaluation methods of Engineering Economics is an efficiency improvement tool in the hands of industrial engineer. Industrial engineering is human effort engineering and system efficiency engineering.


The system functional designers come out with an effective system design that produces an output acceptable to the customer and may also be profitable with reference to the rate of return prescribed by the organization. That does not mean that it is the most efficient solution. In the system engineering process, there is a step in which the proposed basic system is evaluated in various dimensions and further optimization is done. Industrial engineers make efficiency evaluation in various dimensions and further improve the efficiency. Engineering economics is one such area. Engineering economics indicates that search for economic efficiency has to take place on either side of currently proposed engineering equipment. Industrial engineers have to consider various engineering alternatives to the one currently proposed by the system synthesizer to evaluate the current efficiency and if needed propose alternatives that improve the system efficiency using engineering economics methods.




_______________________________________________________________
A Quote


Engineering Economics is applicable to all the fields of engineering since engineers design and make things that people buy. However, it is especially significant to Industrial Engineering, Systems Engineering, and Management Engineering, since these disciplines often are involved in the cost management of engineering systems.


http://www.download-it.org/free_files/Pages%20from%20Chapter%2016%20-%20Engineering%20Economics%20-1faea7ed1d0c63b4b3980e536ad46e1e.pdf


________________________________________________________________

Engineering Economic Appraisal - A Special Role for Industrial Engineers

Engineering economic analysis is to be carried out by all engineers. These analysis reports must be appraised by IE department engineers. IEs can evaluate whether sufficient technical alternatives were considered in proposing the technical solution now recommended and then check the data and calculations of the economic analysis. From IE department, the proposal can go the project appraisal committee.


Engineering Economics is part of Industrial Engineering Tool Kit

Industrial Engineering Tool Kit

_________________________________________________________________

Bibliography


Engineering Economics, John M.Watts, Jr., and Robert E. Chapman
http://fire.nist.gov/bfrlpubs/build02/PDF/b02155.pdf




__________________________________________________________________

Related Knols

Engineering Economy or Engineering Economics: Economic Decision Making by Engineers
Engineering Economics - Knol Book
ngineering Economy or Engineering Economics - Videos

Article originally posted at
http://knol.google.com/k/narayana-rao/engineering-economics-is-an-efficiency/ 2utb2lsm2k7a/ 2270

Introduction to Engineering Economics


Engineers must decide if the benefits of a project exceed its costs, and must make this comparison in a unified framework. The framework within which to make this comparison is the field of engineering economics, which strives to answer exactly these questions, and perhaps more.

______________________________________________________________

It seems peculiar and indeed very unfortunate that so many authors in their engineering books give no, or very little consideration to costs, in spite of the fact that the primary duty of the engineernig is to consider costs in order to obtain real economy- to get the most possible number of dollars and cents: to get the best financial efficiency.
O.B. Goldman, Financial Planning, John Wiley & Sons, New York, 1920.
It would be well if engineering were less generally thought of, and even defined, as the art of constructing. In a certain important sense it is rather the art of not constructing; or, to define it rudely but not ineptly, it is the art of doing that well with one dollar which any bungler can do with two after a fashion.
A.M. Wellington, The Economic Theory of the Location of Railways, John Wiley, New York, 1887
The subject confines of engineering economy were staked out in 1930 by Eugene L. Grant in his book 'Principles of Engineering Economy".
WHY DO ENGINEERS NEED TO LEARN ABOUT ECONOMICS?


Ages ago, the most significant barriers to engineers were technological. The things that engineers wanted to do, they simply did not yet know how to do, or hadn't yet developed the tools to do. There are certainly many more challenges like this which face present-day engineers.
But now, natural resources (from which we must build things) are becoming more scarce and more expensive. We are much more aware of negative side-effects of engineering innovations (such as air pollution from automobiles) than ever before.
For these reasons, engineers are asked more and more to place their project ideas within the larger framework of the environment within a specific planet, country, or region. Engineers must ask themselves if a particular project will offer some net benefit to the people who will be affected by the project, after considering its inherent benefits, plus any negative side-effects (externalities), plus the cost of consuming natural resources, both in the price that must be paid for them and the realization that once they are used for that project, they will no longer be available for any other project(s).
Simply put, engineers must decide if the benefits of a project exceed its costs, and must make this comparison in a unified framework. The framework within which to make this comparison is the field of engineering economics, which strives to answer exactly these questions, and perhaps more.

The Accreditation Board for Engineering and Technology (ABET) states that engineering "is the profession in which a knowledge of the mathematical and natural sciences gained by study, experience, and practice is applied with judgment to develop ways to utilize, economically, the materials and forces of nature for the benefit of mankind".
http://www.isr.umd.edu/~austin/ence202.d/economics.html
Engineering Economics, 4th Edition, James L. Riggs, David D. Bedworth, and Sabah U. Randhawa
McGraw Hill, New York, 1996
MIT Open Courseware
ESD.70J / 1.145J Engineering Economy Module, Fall 2008, Excel based course
Basic Engineering Economics - a PDH Online Course for Engineers

_____________________________________________________________________________

For further explanation of the topic, visit

Management Knols of Narayana Rao are being consolidated in
http://nraomtr.blogspot.com/

__________________________________________________________________________
hits counter


Article Originally posted in
http://knol.google.com/k/narayana-rao/introduction-to-engineering-economics/2utb2lsm2k7a/ 248

Related Article
http://nraomtr.blogspot.com/2011/11/engineering-economy-or-engineering.html

Time Value of Money Calculations

This topic explains the various concepts used to calculate future values or present values of a series of cash flows that result from engineering decisions to buy new equipment or replace old equipments.

Introduction


In one has money in his hand, he can invest it in a bank deposit and after one year he gets back his principal amount and in addition some interest. Therefore $1 today, deposited in a bank at 3% interest per annum will become $1.03 after one year. This is the concept of time value of money. Over time, money increases due to accumulation of interest. Compound interest formula A = P(1 +i)n represents the future value of money.
P = A (1+i)-n represents the present value of money received after n years.

This topic explains the various concepts used to calculate future values or present values of a series of cash flows that result from engineering decisions to buy new equipment or replace old equipments.

Time Value can be present value of a series of future cash flows or future value of series of future cash flows.

Single Payment Cashflow

For a single payment now made, one can calculate a future value. This is done by compounding using the formula A = P(1 +i)n

For a payment to be received in the future, one can calculate the present value. This is done by using discounting formula P = A (1+i)-n

Uniform Periodic Payments

For uniform periodic payments, one can calculate the present value or future value. The payments are assumed to be made at the end of period.

Compounding of uniform series of cash payments

S = R [(1+i)n - 1]/i

where S = Compound amount or future amount at the end of n periods
R = Periodic cash payment at the end of the period
i = rate of interest or required rate of return
n = number of periods for payments are made



Discounting of uniform series of cash payments




P = R [(1+i)n - 1]/[i 1+i)n ]

Where

P = Present Value

R = Uniform series of periodic payments

i = interest rate

n = number of periods of payments

These time value formulas are expressed in factors

A = P*Single payment future worth factor =P*Spfwf

P = A* Single payment present worth factor = A*Sppwf

S = R* Uniform series future worth factor = R*Usfwf

P = R*Unform series present worth factor = R*Uspwf



Two More Factors


Sinking Fund Deposit Factor

Sfdf = 1/Usfwf

Sinking fund is fund accumulated with periodic payments for incurring a lumpsum expenditure at the end of a long period. Sfdf gives the amount to be deposited at the end of each period for n period to accumulate one dollar at the end n periods.

Capital Recovery Factor

Crf = 1/Uspwf

Capital recovery factor gives the uniform payment to be received by you at the end period of n years to get recover back the investment you made today.

The factor tables are available and factors depend on interest rate i and term n.

Factors for a required rate of return of 10% and 5 years term.



Spfwf - 1.6105

Sppwf - .62092

Usfwf - 6.1051

Uspwf - 3.7908

Sfdf - 0.16380

Crf - 0.26380



References

Engineering Economics, 4th Edition, James L. Riggs, David D. Bedworth, and Sabah U. Randhawa, McGraw Hill, New York, 1996

Original knol http://knol.google.com/k/narayana-rao/time-value-of-money/2utb2lsm2k7a/249

Cash Flow Estimation for Expenditure Proposals

For each expenditure proposal, engineers have to estimate revenues and expenditures years wise in the future. They need to estimate salvage values of capital assets at the end of project period.

The cash flow estimation has to follow certain standard practices as they have to be comparable across projects in an organization and in conglomerate companies across various subsidiaries.


Cashflow Estimation - Some Principles

Cash flows of a project have to be estimated for a time horizon. The time horizon is the minimum of physical life of the plant, technological life of the plant, or the product market life.
In estimating the cash flows of a project, incremental principles (that considers all incidental effects), separation of investment and financing principle, post-tax principle and consistency principles are employed.
Incremental principle
In an existing company, the cash flows are to be estimated by evaluating the cash flows of the company with the project and without the project. The difference will be incremental cash flows related to the project.
Separation of investment and financing principle
In a standard capital expenditure analysis, interest payment to be made on borrowings is not brought into the picture. Borrowing is considered a financing decision and its impact is included in the cost of capital estimation. Hence cash flow estimates do not have any interest payment of component.
Post-tax principle
Tax impact on the cash flow is considered and after tax cash flows are estimated.
Consistency principle
The inflation expectation built into estimation of revenues and costs and cost of capital have to be consistent or same.
___________________________________________________________________________________________

Some Examples Issues That I came Across Recently

1. Acquisition of a software by a design department.
2. Replacement of boiler tubes.
3. Replacement of an electronic equipment as some cards used in the equipment are not available anymore for replacement (the equipment manufacturer is not supplying those cards anymore as the equipment is phased out for production).

The approval authority for the expenditures wants the concenred departments to calculate the payback period for the expenditure proposals.



Payback Period

Payback period is an investment appraisal metric. This period will indicate the number of years it will take to get back the cash initially invested in a project. The period is calculated using the estimated cash flows, both outflows and inflows.

Original Knol - http://knol.google.com/k/narayana-rao/payback-period-estimation-of-cash-flows/2utb2lsm2k7a/1952#

Required Rate of Return - Cost of Capital

Visit in this blog only

http://nraomtr.blogspot.com/2011/11/required-rate-of-return-for-investment.html

Depreciation and Other Related Issues

In this blog only visit

Depreciation and Income Tax

http://nraomtr.blogspot.com/2011/11/depreciation-and-income-tax.html

NPV - IRR and Other Summary Project Assessment Measures

NPV Calculation
http://nraomtr.blogspot.com/2011/11/present-worth-comparisons.html


IRR calculation
http://nraomtr.blogspot.com/2011/11/rate-of-return-calculations.html

Equivalent Annual Worth
http://nraomtr.blogspot.com/2011/11/equivalent-annual-worth-comparisons.html

Income Expansion Projects

Projects which increase production capacity and hence give more revenues come under income expansion projects.

Cost Reduction Projects

Some projects can suggest expenditures to improve the efficiency of the machines by adding additional items or by improving certain characteristics of the machine. These projects are cost reduction projects and they need to analyzed using engineering economic analysis.

Industrial engineers are expected to come out with number of cost reduction projects using technologies that claim the cost reduction potential as well as ideas that have cost reduction potential. Lean systems is an idea having cost reduction potential. Lean systems designate certain items as non-value added activities and challenge people to reduce these non-value added activities and reduce cost. Cost of quality or profits of quality system improvement is one such idea. According to it, by redesigning the quality management system, companies can increase profits.

Replacement Decisons

Covered in detail at
http://nraomtr.blogspot.com/2011/11/replacement-analysis.html

Expected Values and Risk of Project Revenues and Costs

For all business expenditure proposals, revenues and costs are estimated for the future years and hence they are subject to the laws of probability and sometimes one may not know even probabilities.

When probabilities can be assigned objectively or subjectively, expected values and risk measures can be calculated for revenues and expenditures and hence for summary measures like NPV and IRR.

Engineering economic analysis used probability calculations.

Engineering Economy or Engineering Economics: Economic Decision Making by Engineers



Engineering Economy: An Explanation

An engineering economy study involves technical considerations and it is a comparison between technical alternatives in which the differences between the alternatives are expressed so far as practicable in money terms (Grant and Ireson, 1960).
Every engineerng decision must be subjected to the question "Will it pay?"
The late General John J.Carty, Chief Engineer of the New York Telephone Company, had asked three questions for every engineering proposal that came to him for review.
1. Why do this at all?
2. Why do it now?
3. Why do it this way?
The first question makes an enquiry regarding profit. In business you do a thing because it is profitable to do so.
The second asks whether the person proposing the investment or expenditure has considered the time alternatives. Can we postpone the investment/expenditure and make more profit?
The third question forces the concerned person to consider all other alternatives to the issue at hand and certify that the solution proposed is the most profitable proposal.
Thus General John Carty made sure that engineering economy studies were done by his technical departments.

 

Economic Decision Making

 
Every dollar an executive proposes to spend or proposes not to spend has to be subjected to economic decision making. If an executive decides to keep a machine in service even though it has frequent breakdowns, giving more number of defective items and consuming more energy, he is making an economic decision. A decision to do nothing is a decision to continue the present production equipment or the system and to reject all alternatives, those which were known and those which were not searched for if he has not searched for them.

Most executives agree that the decision to invest Rs. 5,00,000 for the purchase of a new machine is a typical example of an economic decision. But they do not consider their choice not replacing a machine as an economic decision.

Executives are Unprepared for Economic Decision Making


George A. Taylor in his text book, Managerial and Engineering Economy emphasizes that executives are unprepared for their responsibility in generating and examining alternatives by economic criteria. Most of the executives seldom justify their actions and the resulting expenditure by adequate economic criteria. Too many executives do not a feel a true responsibility for the costs they create or the costs they protect by maintaining the status quo. A designer may take it granted that he has the privilege of creating any cost that may result from is design. He feels costs are the responsibility of the company or somebody else in the company. Proper reflection will make him conclude that costs that result from design are in his sphere of management and hence are his responsibility, because he and not somebody else selected the proposed design from all the possible alternative designs.

If an executive disregards the economic effects of a decision, he is disregarding the cost commitments that will result from his decision.
 

Engineering Efficiency Versus Financial Efficiency

In 1923, O.B. Goldman, who wrote the book, Financial Engineering,  said that the primary duty of the engineer is to consider costs in order to obtain real economy – to get the most power, for example, not from the least number of pounds of steam, but from the least possible number of dollars and cents: to get the best financial efficiency.”
 
The goal of equipment selection in a business system is acceptable financial efficiency, not engineering efficiency.

Searching for  Low Engineering Efficiency Alternatives


If the final choice is based on financial efficiency alone, the search for alternatives must be conducted on either side of current engineering efficiency. Search for higher financial efficiency is not necessarily a search for higher engineering efficiency.

Cost Reduction Expenditures and Income Expansion Expenditures

 Expenditure and Investment proposals can be for cost reduction or income expansion. In some cases, both may be realized.  A characteristic of cost reduction expenditure is that the decision does not affect the gross income. A decision in which the gross income increases is an income expansion proposal. For both the proposals, economic decision making is essential.  

Rate of Return on Capital (Finance)


Finance is the money resources of a business organization. Money resources of an organization consist of equity capital contributed by owners of the firm and loans (short-term as well as long-term) given by various  banks, other firms and individuals. All the entities who provide finance to a firm expect to get back the principal and additional return on principal. The business operations of a firm need have the ability to generate that return or more than that return to acquire capital or finance in the first place and then generate the return to satisfy the expectations afterward. This idea gives rise to cost of capital.
 

Cost of Capital


The user of capital must satisfy the profit motive of the supplier of capital. This obligation of the user of capital is termed as the cost for using capital or cost of capital. Hence all expenditure proposals need to include an evaluation mechanism that considers the cost of capital for the capital required to implement the proposal.

Profit: Accounting and Economics Viewpoints


Profits are measured by accountants. But they are evaluated by economists, engineering economists and financial executives.

The accountant computes profit earned during past periods after incomes and expenses are known. The accountant subtracts expenses from revenue to find the profit on the owner’s investment.
 
The economy analyst or engineering economy analyst tests the profitability of a proposed operation.

Engineering Economy Study

The process of engineering economy study will include data gathering and data analysis.
Analysis requires analytical methods and Engineering Economy texts mainly concentrated on analytical techniques. The analytical techniques express the alternatives in comparable measures of money with respect to their cost, revenue or return on capital.
Data gathering will include some current estimates made by engineers by combining the technical information and costs/prices relevant to the materials and processes used to provide goods or services. The data gathering effort cannot be a one time effort and systems are to be put in place to record appropriate data as and when it first appears. For this purpose accounting sections or departments (financial, cost and management accounting) and technical departments have to jointly work out the need for future engineering economy studies and instal appropriate recording systems.

Is There a Need for Engineer to Involve Themselves in Financial Calculations?

While the financial calculations that necessarily follow the engineers designs and technical estimates are in no sense an exclusive engineering function. Such calculations can be done by persons with accounting background and business administrators.
However, these calculations are such a necessary part of the numerous choices between technical alternatives that every engineer has to do as a part of his design function or process that an engineer who is not equipped to make them is a  poor choice for the job. A deficiency in this matter is particularly serious in an engineer who has administrative responsibility for technnical matters (Grant and Ireson, 1960).
 

References

 
George A. Taylor, Managerial and Engineering Economy, Van Nostrand Reinhold Company, New York, 1964.
Grant, Eugene, L., and W. Grant Ireson, Principles of Engineering Economy, 4th Ed., The Ronald Press Company, 1960, P.3.
___________________________________________________________________________________________

Engineering Economics is an Efficiency Improvement Tool for Industrial Engineers

Engineering Economic Appraisal - A Special Role for Industrial Engineers


Engineering economic analysis is to be carried out by all engineers. These analysis reports must be appraised by IE department engineers. IEs can evaluate whether sufficient technical alternatives were considered in proposing the technical solution now recommended and then check the data and calculations of the economic analysis. From IE department, the proposal can go the project appraisal committee.

Engineering Economics is part of Industrial Engineering Tool Kit

Industrial Engineering Tool Kit

_________________________________________________________________________________

Related Articles






Bibliography

A NEW FRAMEWORK FOR ENGINEERING ECONOMICS
Environmental Engineering Economics Program
Optimal Response to Periodic Shortage: Engineering/Economic Analysis for a Large Urban Water District
Anthony C. Fisher, University of California, Berkeley and Giannini Foundation, David Fullerton, Nile Hatch, Peter Reinelt
Software Engineering Economics

Recently Published Books

Principles of Engineering Economic Analysis, 5th Edition
White, Case, Pratt
ISBN 978-0-470-11396-7, © 2010
Management of Knols are Narayana Rao are being consolidated in
Originally posted in
http://knol.google.com/k/engineering-economy-or-engineering-economics-economic-decision-making-by

Introduction to Engineering Economics

Engineering Economics Revision Article Series

Engineers must decide if the benefits of a project exceed its costs, and must make this comparison in a unified framework. The framework within which to make this comparison is the field of engineering economics, which strives to answer exactly these questions, and perhaps more.

It seems peculiar and indeed very unfortunate that so many authors in their engineering books give no, or very little consideration to costs, in spite of the fact that the primary duty of the engineernig is to consider costs in order to obtain real economy- to get the most possible number of dollars and cents: to get the best financial efficiency.

O.B. Goldman, Financial Planning, John Wiley & Sons, New York, 1920.

It would be well if engineering were less generally thought of, and even defined, as the art of constructing. In a certain important sense it is rather the art of not constructing; or, to define it rudely but not ineptly, it is the art of doing that well with one dollar which any bungler can do with two after a fashion.

A.M. Wellington, The Economic Theory of the Location of Railways, John Wiley, New York, 1887

The subject confines of engineering economy were staked out in 1930 by Eugene L. Grant in his book 'Principles of Engineering Economy".

WHY DO ENGINEERS NEED TO LEARN ABOUT ECONOMICS?

Ages ago, the most significant barriers to engineers were technological. The things that engineers wanted to do, they simply did not yet know how to do, or hadn't yet developed the tools to do. There are certainly many more challenges like this which face present-day engineers.

But now, natural resources (from which we must build things) are becoming more scarce and more expensive. We are much more aware of negative side-effects of engineering innovations (such as air pollution from automobiles) than ever before.

For these reasons, engineers are asked more and more to place their project ideas within the larger framework of the environment within a specific planet, country, or region. Engineers must ask themselves if a particular project will offer some net benefit to the people who will be affected by the project, after considering its inherent benefits, plus any negative side-effects (externalities), plus the cost of consuming natural resources, both in the price that must be paid for them and the realization that once they are used for that project, they will no longer be available for any other project(s).

Simply put, engineers must decide if the benefits of a project exceed its costs, and must make this comparison in a unified framework. The framework within which to make this comparison is the field of engineering economics, which strives to answer exactly these questions, and perhaps more.



The Accreditation Board for Engineering and Technology (ABET) states that engineering "is the profession in which a knowledge of the mathematical and natural sciences gained by study, experience, and practice is applied with judgment to develop ways to utilize, economically, the materials and forces of nature for the benefit of mankind".

http://www.isr.umd.edu/~austin/ence202.d/economics.html



Engineering Economics, 4th Edition, James L. Riggs, David D. Bedworth, and Sabah U. Randhawa
McGraw Hill, New York, 1996


MIT Open Courseware
ESD.70J / 1.145J Engineering Economy Module, Fall 2008, Excel based course
http://ocw.mit.edu/OcwWeb/Engineering-Systems-Division/ESD-70JFall-2008/CourseHome/index.htm

A NEW FRAMEWORK FOR ENGINEERING ECONOMICS
Basic Engineering Economics - a PDH Online Course for Engineers

Article Originally posted in
http://knol.google.com/k/narayana-rao/introduction-to-engineering-economics/2utb2lsm2k7a/248

Engineering Economics or Economy - Typical Problems

1. Repairs to a factory roof can be made today for $4,000. If repairs are postponed, it will have to be replaced in 3 years for $6,000. Both the repaired roof and new roof will have similar technical life and last long. If the company's minimum required rate of return is 30%, should the repairs be made?

Sppwf (32%, 3 years) = 0.435


2. By spending $30,000 for a conveyor, a factory expects to save $6,000 a year for the next 7 years in the cost of handling material. The conveyor belt will have zero salvage value at that end of 7 years. If the cost of capital for the project is 18%, should the company invest in this project?

Uspwf(18%,7 years) = 3.812


3. A company can overhaul a machine now for $2000. It can wait unit the end of the year also. But during the year it will suffer a cost $400 due to idle labor. If the cost of capital is 20%, what is the right decision?

Spfwf(20%,1year) = 1.2


4. A machine needs to be maintained at a cost of $500 at the end of the year, and this cost is expected to increase by $50 a year over its 10 years further life. A overhaul of the machine costs $2000$ and this will reduce the maintenace expenditure to $100 per year. Should the company go for the overhaul if its minimum rate of return required is 20%?

Uspwf (20%,10 years) = 4.193


5. A company can purchase a new special-purpose lathe for $7,500 installed cost. The annual cost of running this machine that includes labor, power, and maintenance, is $2,500. The other alternative is a general purpose machine that can be installed for $4,500 and the anual cost is $3,250 a year. The life of both the machines is expected to be 10 years and the salvage values are expected to be $750 and $500. If the company's minimum required rate of return is 15%, which machine should be recommended?

Sppwf (15%,10years) = 0.247; Uspwf (15%,10 years) = 5.019


Originally posted in
http://knol.google.com/k/narayana-rao/engineering-economics-or-economy/2utb2lsm2k7a/713

Time Value of Money

Engineering Economics Revision Article Series

This topic explains the various concepts used to calculate future values or present values of a series of cash flows that result from engineering decisions to buy new equipment or replace old equipments.

Introduction


In one has money in his hand, he can invest it in a bank deposit and after one year he gets back his principal amount and in addition some interest. Therefore $1 today, deposited in a bank at 3% interest per annum will become $1.03 after one year. This is the concept of time value of money. Over time, money increases due to accumlulation of interest. Compound interest formula A = P(1 +i)n represents the future value of money.
P = A (1+i)-n represents the present value of money received after n years.
 
This topic explains the various concepts used to calculate future values or present values of a series of cash flows that result from engineering decisions to buy new equipment or replace old equipments.
 
Time Value can be present value of a series of future cash flows or future value of  series of future cash flows.
 

Single Payment Cashflow 

 
For a single payment now made, one can calculate a future value. This is done by compounding using the formula  A = P(1 +i)n
 
For a payment to be received in the future, one can calculate the present value. This is done by using discounting formula P = A (1+i)-n
 

Uniform Periodic Payments

 
For uniform periodic payments, one can calculate the present value or future value. The payments are assumed to be made at the end of period.
 
Compounding of uniform series of cash payments
 
S = R [(1+i)n - 1]/i
 
where S = Compound amount or future amount at the end of n periods
R = Periodic cash payment at the end of the period
i = rate of interest or required rate of return
n = number of periods for payments are made
 

 

Discounting of uniform series of cash payments

 

P = R [(1+i)n - 1]/[i 1+i)n ]

Where

P = Present Value

R = Uniform series of periodic payments

i = interest rate

n = number of periods of payments

These time value formulas are expressed in factors

A = P*Single payment future worth factor  =P*Spfwf

P = A* Single payment present worth factor = A*Sppwf

S = R* Uniform series future worth factor = R*Usfwf

P = R*Unform series present worth factor = R*Uspwf

 

Two More Factors

 

Sinking Fund Deposit Factor

Sfdf = 1/Usfwf

Sinking fund is fund accumulated with periodic payments for incurring a lumpsum expenditure at the end of a long period. Sfdf gives the amount to be deposited at the end of each period for n period to accumulate one dollar at the end n periods.

Capital Recovery Factor

Crf = 1/Uspwf

Capital recovery factor gives the uniform payment to be received by you at the end period of n years to get recover back the investment you made today.

 The factor tables are available and factors depend on interest rate i and term n.

Factors for a required rate of return of 10% and 5 years term.

 

Spfwf - 1.6105

Sppwf - .62092

Usfwf - 6.1051

Uspwf - 3.7908

Sfdf - 0.16380

Crf -  0.26380

 

References

Engineering Economics, 4th Edition, James L. Riggs, David D. Bedworth, and Sabah U. Randhawa, McGraw Hill, New York, 1996

 

 

Visit http://nraomtr.blogspot.com/  for Management Knols of Narayana Rao

hits counter Originally Posted in
http://knol.google.com/k/narayana-rao/time-value-of-money/2utb2lsm2k7a/ 249

Present-Worth Comparisons

Engineering Economics Revision Article Series

Net present worth (NPW) or Net present value (NPV) is the difference between the present worths of benefits and costs of an engineering decision. It is the most widely used present-worth model.

Illustrative Problem

A single underground transmission circuit is needed immediately, and load studies indicate the need for a second circuit in 6 years. If provision is made for a second conduit when the conduit for the first circuit is installed, there will be no future need for reopening, trenching, backfillng, and repaving.

the cost of installing a single circuit wiht minimum preparation for the eventual second circuit is $850,000. the installation of the second circuit will be considered to cost $800,000 at the end of year 6 in order to be in operation by the beginning of year 7. If the second circuit is installed immediately, the total cost will be $1.4 million.

Constant annual operating and maintenance costs of the circuits are 8 percent of the first cost. The average life of a circuit is 20 years. The required rate of return on such investments is 10 percent before taxes.

To take a decision, Comparison of the deferred investment with the immediate investment needs to be made.
(Exercise Problem 3.25, Riggs)
References

Engineering Economics, 4th Edition, James L. Riggs, David D. Bedworth, and Sabah U. Randhawa, McGraw Hill, New York, 1996

http://knol.google.com/k/narayana-rao/present-worth-comparisons/2utb2lsm2k7a/250

Updated 21.4.2012

Required Rate of Return for Investment or Expenditure Proposal

Engineering Economics Revision Knol Series
Each business expenditure proposal that holds forth prospects of profits can be termed as investment. Investment is defined as spending money with the expectation of profits.

Business firms are users of capital. The user of capital has to satisfy the profit motive of the suppliers of capital. There is cost for using capital.

Introduction - Business Expenditure or Investment

Each business expenditure proposal that holds forth prospects of profits can be termed as investment. Investment is defined as spending money with the expectation of profits.

Deferment of present ability to consume to a future period is done by persons due to profit motive. The profit motive can be explained as the inducement that causes man to forego satisfying his present desires based on the prospects of satisfying greater ones in the future. Thus, every individual is motivated by profit for his personal investment decisions or deferment of consumption decisions. Professional managers of corporations are being paid to perform activities that satisfy the profit motive of the corporation's shareholders.

Cost of Capital and Profit Motive

Business firms are users of capital. The user of capital has to satisfy the profit motive of the suppliers of capital. There is cost for using capital. The cost may be a contractual obligation in case of loans and bonds. It good be a good faith obligation in case of equity capital. The manager is charge of the firm is expected to undertake activities in line with the business plans and execute them to obtain the expected profit.

Sources of Return

Capital is productive. It is continuously invested in fresh investment or expenditure opportunities that yield more profit than the current projects. From this statement, the concept of opportunity cost arises. Whenever any person is contemplating a new expenditure proposal money is being diverted to the new proposal from an old project or currently planned project. The return anticipated from the current project is the floor for the new project. The new project has to give a rate of return that is higher than that of the current selected opportunity. Thus every new proposal has an opportunity cost of capital.

Every proposal that clears the test of opportunity cost of capital is giving profit. Thus owners of capital or professional managers invest their capital in efficient proposals that give profits.

Determination of Cost of Capital

A corporation's capital is sourced from variety of suppliers. Equity Capital, Preferred Share Capital, Profits Retained or Ploughed back and debt capital are the main instruments through which capital is acquired by companies or corporations. To estimate the total cost of capital, the cost of each source of capital is to be first estimated. Then the weight of each source of capital in determined and the weighted average of various costs of capital gives the company cost of capital. This exercise can be done for each proposed project.

Originally posted in
http://knol.google.com/k/narayana-rao/required-rate-of-return-for-investment/2utb2lsm2k7a/1200

Rate-of-Return Calculations

Engineering Economics Revision Article Series

Internal rate of return (IRR) of an engineering decision can be compared with the minimum acceptable rate of return set by the organization.

IRR is calculated by equating the annual, or present, or future worth of cash flows to zero and solving for the interest rate that allows the equality

References


Engineering Economics, 4th Edition, James L. Riggs, David D. Bedworth, and Sabah U. Randhawa, McGraw Hill, New York, 1996


Online Resources
http://www.ie.bilkent.edu.tr/~ie342-3/Lecture%20No25.ppt


_____________ _____________

_____________ _____________

_____________ _____________
Originally posted in
http://knol.google.com/k/narayana-rao/rate-of-return-calculations/2utb2lsm2k7a/ 252

Equivalent Annual-Worth Comparisons

Engineering Economics Revision Article Series

With an annual worth method, all the receipts and disbursements occuring over a period of time due to an engineering alternative are converted to an equivalent uniform yearly payment. Such a calculation can give annual cost of various alternative engineering alternatives.

References

Engineering Economics, 4th Edition, James L. Riggs, David D. Bedworth, and Sabah U. Randhawa, McGraw Hill, New York, 1996


For more details

http://ise.tamu.edu/people/faculty/butenko/INEN303/chap6.pdf

Problems and Solutions on Equivalent Annual Worth



Originally posted in
http://knol.google.com/k/narayana-rao/equivalent-annual-worth-comparisons/2utb2lsm2k7a/ 251
 
Designed By An Insurance | Proudly Powered by Blogger