New blog ... not for the faint hearted :)

I've started a new blog, titled "Career Development ToDo" where I am cataloging efforts, skills and knowledge that would eventually build me into a well rounded, professional.

At this stage I am concentrating on Quality, Project Management and Telecom.

URL: http://career-development-todo.blogspot.com/

I welcome feedback, suggestions and contributions.

Earned Value Management - explaining the formulae

Start with the 3 corner stones of EVM; there's no need to "understand" what they stand for, at least for the time being.

AC = Actual Cost

EV = Earned Value

PV = Planned Value

Unfortunately, as PMI tends to use old EVM nomenclature, we need the old 3 terms too:

ACWP = Actual Cost of Work Performed = obviously the Actual Cost = AC

BCWP = Budgeted Cost of Work Performed = expected value of work performed = EV

BCWS = Budgeted Cost of Work Scheduled = expected value of work planned = PV

Now that the old and new terms are explained and understood it's time to tackle the formulae.

Remember, EVM is used for measuring and monitoring performance, and the best way to measure performance is to compare it against another value and determine the differences, ie: Variances and Ratios, ie: Cost Variance (CV), Schedule Variance (SV), Cost Performance Index (CPI) and Schedule Performance Index (SPI).

By the way, variances are good only if they're positive, and ratios are good only when they're greater than 1.

Variances: To enforce the effect of AC and EV, they should be in a position where they influence a positive result; ie: smaller AC and larger EV. Presto!

CV = difference between cost incurred (AC) and value expected (EV)

      = EV - AC (smaller AC => positive result, larger AC => negative)

      = BCWP - ACWP

SV = difference between value expected and value planned

      = difference between Earned Value (EV) and Planned Value (PV)

      = EV - PV (larger EV => positive result; smaller EV => negative)

      = BCWP - BCWS

Performance Ratios: Still following the "smaller AC and larger EV" and using them in a ratio to yield greater than 1 value, gives:

CPI = ratio between cost incurred (AC) and value expected (EV)

        = EV/AC

        = BCWP/ACWP

SPI = ratio between value earned (EV) and value expected (PV)

        = EV/PV

        = BCWP/BCWS

Yielding to Project managers' need for putting everything into percentages, the Variance% needs the variance to be represented as a percentage (%) of value that is earned (EV).

CV% = CV/EV * 100

SV% = SV/EV * 100

All the above values are part of the "monitoring: performed using EVM.

"Controlling" would mean changing and forecasting new values, ie: new "Estimates".

Estimate To Complete (ETC) = estimate of how much more expenditure is needed from this point. If all has gone well it would be the difference between budgeted cost (at completion, BAC) and actual cost (AC).

Estimate At Completion (EAC) = estimate of total cost that the project would eventually incur. In an ideal world this would be the same as original planned budget (BAC).

But, all doesn't go always well, so there are some more terms and formulae:

BAC = The planned budget of the project, obviously a known value. Hence no need for a formula

EAC = BAC; if original budgeting holds good; here CPI = 1, CV = 0

(1)    = BAC/CPI                      ; factoring in CPI

(2)    = BAC/CPI - CV               ; factoring in CV

(2)    = BAC/CPI - EV + AC        ; replacing the formula for CV

(3)    = BAC/CPI - EV/CPI + AC ; if present performance is not 

                                                expected to continue CPI affects EV

(3)     = (BAC - EV)/CPI + AC

(4)     = ETC + AC                   ; older budgeting totally a mess!

ETC = BAC - AC                    ; if all is well, which of course it isn't

        = EAC - AC                   ; so factor in new estimates, ie: EAC

And the final measure of whether the entire project is over or under budget, ie: Variance At Completion (VAC) is the difference between original budget (BAC) and revised estimate (EAC)

VAC = BAC - EAC

Galaxy Triplet ..

On April 1-2, 2009 the Hubble Space Telescope photographed this winning target in the Space Telescope Science Institute’s 'You Decide' competition in celebration of the International Year of Astronomy (IYA).

The winner is a group of galaxies called Arp 274 . The striking object received 67,021 votes out of the nearly 140,000 votes cast for the six candidate targets.

Arp 274, also known as NGC 5679, is a system of three galaxies that appear to be partially overlapping in the image, although they may be at somewhat different distances. The spiral shapes of two of these galaxies appear mostly intact. The third galaxy (to the far left) is more compact, but shows evidence of star formation.

Two of the three galaxies are forming new stars at a high rate. This is evident in the bright blue knots of star formation that are strung along the arms of the galaxy on the right and along the small galaxy on the left.

The largest component is located in the middle of the three. It appears as a spiral galaxy, which may be barred. The entire system resides at about 400 million light-years away from Earth in the constellation Virgo.

Hubble's Wide Field Planetary Camera 2 was used to image Arp 274. Blue, visible and infrared filters were combined with a filter that isolates hydrogen emission. The colors in this image reflect the intrinsic color of the different stellar populations that make up the galaxies. Yellowish older stars can be seen in the central bulge of each galaxy. A bright central cluster of stars pinpoint each nucleus. Younger blue stars trace the spiral arms, along with pinkish nebulae that are illuminated by new star formation. Interstellar dust is silhouetted against the starry population. A pair of foreground stars inside our own Milky Way are at far right.

The International Year of Astronomy is the celebration of the 400th anniversary of Galileo's first observations with a telescope. People around the world came together to participate in the IYA's 100 Hours of Astronomy, April 2 to 5. This global astronomy event was geared toward encouraging as many people as possible to experience the night sky.


Image Credit: NASA, ESA, and M. Livio and the Hubble Heritage Team (STScI/AURA)