Formulas Flashcards
Analogous Estimating
Described in section 6.4.2.2 uses value or attributes of a previous project that area similar to the current project values and attributes of the projects may include but are not limited to scope, cost, budget, duration, and measures of scale ( eg size, weight). Comparison of these project variables or attributes, become the basis for estimating the same parameter or measurement for the current project
Parametric Estimating
6.4.2.3 Parametric measuring uses a statistical relationship between relevant historical data and other variables ( eg square footage in a building construction) to calculate a cost estimate for project work. This technique can produce higher levels of accuracy depending on the sophistication and underlying data built in to the model. Parametric cost estimates can be applied to a total project or t osegments of a project, in conjunction with other estimating methods.
Parametric
of relating to a parameter. A constant in an equation that vary in other equations in general form One set of measurable factors. such as temperature and pressure that define a system and determine its behavior and are varied in an experiment.
analogous
Similar or alike in such a way as to permit the drawing of an analogy, similar or corresponding in some respect
Bottom up estimating
6.4.2.5 Bottom up estimating is a method of estimating a component of work the cost of individual work packages or activities is estimated to be the greatest level of specified detail. The detailed cost is then summarized or rolled up to higher levels for subsequent reporting and tracking purposes. The cost and accuracy of bottom up cost estimating are typically influenced by the size or other attributes of the individual activity or work percentage.
Three Point estimating
6.4.2.4 The accuracy of single point cost estimates may be improved by considering estimation uncertainty and risk using three estimates to define an approximate range for an activities cost
Most likely (cM)
The cost of an activity, based on realistic effort assessment for the required work and any predicted expenses.
Optimistic (cO)
The cost based on analysis on the best case scenario for the activity
Pessimistic
The cost based on analysis of the worst case scenario for the activity
Three point estimating finish sentence
Depending on the assumed distribution of values withing the range of the three estimates, the expected cost can be calculated using a formula. tow commonly used formulas are triangular and beta distributions.
Expected Cost (cE)
(cE)
Optimistic
(cO)
Most likely
(cM)
Triangular distribution
cE= (cO +cM+cP)/3
Triangular distribution in words
expected cost= (optimistic cost + most likely cost + pessimistic cost) /3
Beta distribution
cE= (cO + 4cM +cP)/6
beta distribution in words
expected cost = optimistic + 4* most likely cost +pessimistic cost)/6
Cost estimate statement
Cost estimates based on three points with an assumed distribution provide an expected cost and clarify the range of uncertanty around the expected cost
Data analysis
Data analysis techniques that can be used in the estimate costs process include but are not limited to Alternative analysis, Reserve analysis, cost of quality
Alternative analysis
alternative analysis is a technique used to evaluate identified options in order to select which options or approaches to use to execute and perform the work of the project. An example would be evaluating the cost, schedule, resource and quality impacts of buying versus making a deliverable
Reserve analysis
cost estimates may include contingency reserves or contingency allowances to account for cost uncertainty. Contingency reserves are the budget within the cost baseline that is allocated for identified risks. Contingency reserves are often viewed as part of the budget intended to address the known unknowns that can affect a project. Foe example, re work for some project deliverables could be anticipated, while the amount of this rework is unknown. Contingency reserves may be estimated to account for this unknown amount of re work. Contingency reserves can be provided at any level from the specified activity to the entire project. The contingency reserve may be a percentage of the estimated cost, a fixed number, or may be developed by using quantitative analysis methods. As more precise information about the project becomes available, the contingency reserve may be used, reduced, or eliminated. Contingency should be clearly identified in cost documentation. Contingency reserves are part of the cost baseline and the overall funding requirement for the project.
Contingency reserves AKA
AKA contingency allowances
Contigency reserves
contingency reserves are the budget within the cost baseline that is allocated for identified risks
Cost of quality
Assumptions about cost of quality (8.1.2.3) may be used to prepare the estimates. This included evaluating the cost impact of additional investment in conformance versus the cost of non conformance. It can also include looking at short -term cost reductions versus the implication of more frequent problems later on in the product life cycle.
PV
Planned value
PV definition
The authorized budget assigned to scheduled work. The value of the work planned to be completed t oa point in time, usually the data table, or project completion
EV
Earned value
EV definition
The measure of work performed expressed in terms of the budget authorized for that work,
EV how it’s used
The planned value of all of the work completed (earned) to a point in time, usually the data date, without reference to actual cost
EV formula
Ev= sum of the planned value of completed work
AC
Actual cost
AC definition
The realized cost incurred for the work performed on an activity during a specified time period
AC how it’s used
The actual cost of all of the work completed to a point in time ,usually the data date
BAC
Budget at comparison
BAC Definition
The sum of all budgets established for the work to be performed
BAC
The value of total planned work, the project baseline
product baseline
BAC
CV Definition
Cost variance
CV definition
The amount of budget deficit or surplus at a given point in time, expressed as the difference between the earned value and the actual cost
CV how its used
The difference between the work completed to a point in time usually the data date. and the actual costs at the same point in time
CV equation
CV= EV-AC
CV equation in words
Cost variance = earned value - actual cost
CV interpretation of results
Positive- under planned costs, Neutral on planned costs, negative over planned cost
SV
Schedule varience
SV definition
The amount by which the project is ahead or behind the planned delivery date, at a given point in time, expressed as the difference between the budget at completion and the estimate at completion
SV how is it used
The difference between the work completed to a point in time , usually the data date, and the work planned to be completed to the same point
SV formula
SV=EV-PV
SV formula in words
Schedule variance is = earned value- planned value
SV interpretation of results
Positive= ahead of schedule, Neutral on schedule, Negative behind schedule
VAC
Variance at completion
VAC definition
A projection of the amount of budget defecit or surplus expressed as the difference between the budget at completion and the estimate at completion
VAC how its used
The estimated difference in cost at the completion of a project
VAC formula
VAC= BAC-EAC
VAC formula in words
Variance at completion= budget at completion -estimate at completion
VAC interpretation of results
Positive - under planned cost, Neutral - on planned cost, Negative - under planned cost
CPI
Cost performance index
CPI definition
A measure of the cost efficiency of budgeted resources expressed as the ration of earned value to actual cost
CPI how it’s used
A CPI of 1.0 means the project is exactly on budget, that the work actually done so far is exactly done so far is exactly the same as the cost so far. Other values show the percentage of how much costs are over or under the budgeted amount of work accomplished
CPI formula
CPI= EV/AC
CPI formula in words
cost performance index= earned value/actual cost
CPI Interpretation of result
Greater than 1.0 under planned cost, exactly 1.0 on planned cost. Less than 1.0 behind schedule
SPI
Schedule Performance Index
SPI definition
A measure of schedule efficiency expressed as the ratio of earned value to planned value
SPI how its used
A SPi of 1.0 means that the project is exactly on schedule. that the work actually done so far is exactly the same as the work planned to be done so far. Other values show the percentage of how much costs are under or over the budgeted amount for work planned.
SPI formula
SPI= EV/PV
SPI formula in words
Schedule Performance index =Earned value/ Planned value
SPI interpretation of results
Greater than 1.0 ahead of schedule, 1.0 on schedule, less than 1.0 behind schedule
EAC
Estimate at completion
EAC definition
The expected cost to finish all of the remaining project work
EAC how its used
If the CPI is expected to be the same for the remainder of the project, EAC can be calculated using EAC= BAC/CPI
EAC formula CPI the same for the rest of the project
EAC=BAC/CPI
EAC formula CPI the same in words
estimate at completion = budget at completion/cost performance index
EAC formula if future work will be accomplished at the planned rate
EAC= AC+BAC-EV
EAC formula if future work will be accomplished at the planned rate in words
estimate at completion= Actual cost +budget at completion-earned value
EAC formula if the initial plan is no longer valid
EAC= AC+ Bottom up ETC
EAC if both the CPI and SPI influence the remaining work use this formula
EAC= AC +[(BAC-EV)/(CPI*SPI)]
EAC if both the CPI and SPI influence the remaining work use formula in words
Estimate to completion = Actual cost +{(budget at completion-earned value)/(Cost Performance Index*Schedule Performance Index)]
ETC
Estimate to complete
ETC definition
The expected cost to finish all the remained work project
ETC How it’s used
Assuming work is proceeding on plan, the cost of completing the remaining authorized work can be calculated using
ETC Proceeding on plan formula
ETC= EAC-AC
ETC proceeding on plan formula words
estimate at complete = Estimate at completion-Actual Cost
ETC formula for re estimate the remaining work from the bottom up
ETC= re estimate
TCPI
To complete performance index
TCPI definition
A measure of the cost performance that must be achieved wit the remaining resources in order to meet a specified management goal., expressed as the ratio of the cost to finish the outstanding work to the budget available.
TCPI how it’s used
The efficiency that must be maintained in order to complete on the plan
TCPI formula the efficiency that must be maintained in order to complete on plan
TCPI= (BAC-EV)/(BAC-AC)
TCPI formula the efficiency that must be maintained in order to complete on plan in words
To complete performance index = (Budget at completion- earned value)/(Budget at completion-Actual cost)
TCPI the efficiency that must be maintained in order to complete on plan Interpretation of result
greater than 1.0= harder to complete/ exactly 1.0 same to complete- less than 1.0 easier to complete
TCPI how it’s used part 2
the efficiency that must be maintained in order to complete the current EAC- (Estimate at Completion)
TCPI the efficiency that must be maintained in order to complete the current EAC formula
TCPI=(BAC-EV)/EAC-AC)
TCPI the efficiency that must be maintained in order to complete the current EAC formula in words
To complete performance index= (Budget at Completion-Earned value)/(estimate at completion-actual cost)
TCPI the efficiency that must be maintained in order to complete the current EAC interpretation of results
Greater than 1.0 Harder to complete, exactly 1.0 same to complete, Less than 1.0 easier to complete
Communication channels formula
N(n-1)/2
