Budžets pabeidzot vs Aprēķins pabeidzot (BAC vs EAC)
Visbiežāk pārprastais jēdziens Earned Value Management ir attiecība starp Budžetu pabeidzot (BAC) un Aprēķinu pabeidzot (EAC). Tie izskatās līdzīgi, tie abi atspoguļo "kopējās projekta izmaksas", bet tie darbojas pilnīgi pretēji.
BAC = izmaksas, kuras jūs plānojāt pirms projekta sākuma. Tās ir fiksētas.
EAC = izmaksas, kuras jūs pašlaik prognozējat pabeigšanai. Tās mainās projektam attīstoties.
Ātrs salīdzinājums: BAC vs EAC
| Īpašība | BAC (Budžets pabeidzot) | EAC (Aprēķins pabeidzot) |
|---|---|---|
| Definīcija | Kopējais apstiprinātais bāzes budžets | Prognozētās kopējās projekta izmaksas |
| Kad noteikts | Vienreiz, projekta sākumā | Pārrēķināts izpildes laikā |
| Mainās? | Tikai formāli pārskatot bāzes līniju | Jā — tiek atjaunināts katrā pārskata periodā |
| Pamatojas uz | Tikai plānotajiem novērtējumiem | Faktiskajām izmaksām + veiktspējas indeksiem |
| Formula | Σ (visi darba pakešu budžeti) | BAC / CPI (izplatītākā no 4 formulām) |
| PMBOK ref. | 6. izdevums 263. lpp. | 6. izdevums 264.–265. lpp. |
Projekta sākumā: BAC = EAC
Brīdī, kad tiek apstiprināta projekta bāzes līnija, BAC un EAC ir identiski. Nekādi darbi nav veikti, nekādas faktiskās izmaksas nav radušās, un veiktspēja ir tieši tāda, kā plānots. Tiklīdz sākas izpilde un parādās reāli dati (AC, EV), EAC sāk atšķirties no BAC.
Kāda ir atšķirība starp BAC un EAC?
Atšķirība starp BAC un EAC ir Novirze pabeidzot (VAC). VAC ir galīgā budžeta pārpalikuma vai deficīta prognoze, pamatojoties uz novēroto veiktspēju.
Apskatīsim šo piemēru: programmatūras projekts ar BAC = $400,000.
- Pēc 3 mēnešiem: AC =
Budget at Completion vs Estimate at Completion (BAC vs EAC)
The most common point of confusion in Earned Value Management is the relationship between Budget at Completion (BAC) and Estimate at Completion (EAC). They look similar, they both represent a "total project cost", but they behave in completely opposite ways.
BAC = the cost you planned before the project started. It is fixed.
EAC = the cost you currently forecast to finish. It changes as the project evolves.
Quick Comparison: BAC vs EAC
Property BAC (Budget at Completion) EAC (Estimate at Completion) Definition Total approved baseline budget Forecasted total project cost When set Once, at project baseline Recalculated throughout execution Changes? Only via formal re-baselining Yes — updated every reporting period Based on Planned estimates only Actual cost + performance indices Formula Σ (all work package budgets) BAC / CPI (most common of 4 formulas) PMBOK ref. 6th Ed. p.263 6th Ed. p.264–265 At Project Start: BAC = EAC
At the moment a project baseline is approved, BAC and EAC are identical. No work has been performed, no actual costs have been incurred, so the forecast equals the plan. As soon as execution begins and real data appears (AC, EV), EAC starts to diverge from BAC.
What is the difference between BAC and EAC?
The key distinction: BAC represents commitment — what was formally agreed with stakeholders. EAC represents reality — what the project is actually projected to cost based on observed performance.
Consider this example: a software project with BAC = $400,000.
- After 3 months: AC = $130,000, EV = $100,000 (25% complete)
- CPI = EV / AC = 100,000 / 130,000 = 0.769 (over budget)
- EAC = BAC / CPI = 400,000 / 0.769 = $520,156
- VAC = BAC − EAC = 400,000 − 520,156 = −$120,156 (projected overrun)
BAC is still $400,000. EAC is now $520,156. The $120,156 gap is what the project manager needs to explain and manage.
Can BAC change during a project?
Yes, but only through a formal process. BAC changes in two scenarios:
- Approved scope change — Additional work packages are added via change control, increasing (or decreasing) the authorized budget.
- Re-baselining — Senior management formally approves a new cost baseline, typically when the original BAC is no longer achievable and a fresh start is needed. This is a significant governance event.
Cost overruns alone NEVER change BAC. They are reflected in EAC and VAC instead.
What does it mean when EAC exceeds BAC?
When EAC exceeds BAC (VAC is negative), the project is projected to finish over budget. The difference represents the forecasted cost overrun. Project managers must report this to stakeholders and take corrective action to drive CPI closer to 1.0 — which reduces EAC.
Research cited in PMBOK shows that once CPI drops below 0.9, it rarely recovers significantly after the 20% completion mark. This makes early EAC forecasting critical.
When EAC is Below BAC
When EAC is less than BAC, VAC is positive — the project is forecast to finish under budget. This is favorable and represents a budget surplus.
The 4 EAC Formulas and How They Relate to BAC
All four PMBOK EAC formulas reference BAC:
EAC₁ = BAC / CPI ← typical performance continues (most common)
EAC₂ = AC + (BAC − EV) ← one-time variance; future at planned rate
EAC₃ = AC + (BAC − EV) / CPI ← sustained CPI impact (= EAC₁)
EAC₄ = AC + (BAC − EV) / (CPI × SPI) ← schedule pressure adds costThe relationship between BAC and each EAC determines VAC = BAC − EAC. The formula you choose reflects your assumption about future performance — but all four start from the same fixed BAC.
Summary Table
→ Calculate BAC, EAC and VAC Instantly 30,000, EV =Situation BAC EAC VAC Meaning On track $500K $500K $0 On budget Cost overrun $500K $560K −$60K Projected to exceed budget Under budget $500K $470K +$30K Forecast surplus Re-baselined $580K $580K $0 New approved baseline Budget at Completion vs Estimate at Completion (BAC vs EAC)
The most common point of confusion in Earned Value Management is the relationship between Budget at Completion (BAC) and Estimate at Completion (EAC). They look similar, they both represent a "total project cost", but they behave in completely opposite ways.
BAC = the cost you planned before the project started. It is fixed.
EAC = the cost you currently forecast to finish. It changes as the project evolves.
Quick Comparison: BAC vs EAC
Property BAC (Budget at Completion) EAC (Estimate at Completion) Definition Total approved baseline budget Forecasted total project cost When set Once, at project baseline Recalculated throughout execution Changes? Only via formal re-baselining Yes — updated every reporting period Based on Planned estimates only Actual cost + performance indices Formula Σ (all work package budgets) BAC / CPI (most common of 4 formulas) PMBOK ref. 6th Ed. p.263 6th Ed. p.264–265 At Project Start: BAC = EAC
At the moment a project baseline is approved, BAC and EAC are identical. No work has been performed, no actual costs have been incurred, so the forecast equals the plan. As soon as execution begins and real data appears (AC, EV), EAC starts to diverge from BAC.
What is the difference between BAC and EAC?
The key distinction: BAC represents commitment — what was formally agreed with stakeholders. EAC represents reality — what the project is actually projected to cost based on observed performance.
Consider this example: a software project with BAC = $400,000.
- After 3 months: AC = $130,000, EV = $100,000 (25% complete)
- CPI = EV / AC = 100,000 / 130,000 = 0.769 (over budget)
- EAC = BAC / CPI = 400,000 / 0.769 = $520,156
- VAC = BAC − EAC = 400,000 − 520,156 = −$120,156 (projected overrun)
BAC is still $400,000. EAC is now $520,156. The $120,156 gap is what the project manager needs to explain and manage.
Can BAC change during a project?
Yes, but only through a formal process. BAC changes in two scenarios:
- Approved scope change — Additional work packages are added via change control, increasing (or decreasing) the authorized budget.
- Re-baselining — Senior management formally approves a new cost baseline, typically when the original BAC is no longer achievable and a fresh start is needed. This is a significant governance event.
Cost overruns alone NEVER change BAC. They are reflected in EAC and VAC instead.
What does it mean when EAC exceeds BAC?
When EAC exceeds BAC (VAC is negative), the project is projected to finish over budget. The difference represents the forecasted cost overrun. Project managers must report this to stakeholders and take corrective action to drive CPI closer to 1.0 — which reduces EAC.
Research cited in PMBOK shows that once CPI drops below 0.9, it rarely recovers significantly after the 20% completion mark. This makes early EAC forecasting critical.
When EAC is Below BAC
When EAC is less than BAC, VAC is positive — the project is forecast to finish under budget. This is favorable and represents a budget surplus.
The 4 EAC Formulas and How They Relate to BAC
All four PMBOK EAC formulas reference BAC:
EAC₁ = BAC / CPI ← typical performance continues (most common)
EAC₂ = AC + (BAC − EV) ← one-time variance; future at planned rate
EAC₃ = AC + (BAC − EV) / CPI ← sustained CPI impact (= EAC₁)
EAC₄ = AC + (BAC − EV) / (CPI × SPI) ← schedule pressure adds costThe relationship between BAC and each EAC determines VAC = BAC − EAC. The formula you choose reflects your assumption about future performance — but all four start from the same fixed BAC.
Summary Table
→ Calculate BAC, EAC and VAC Instantly 00,000 (pabeigti 25%)Situation BAC EAC VAC Meaning On track $500K $500K $0 On budget Cost overrun $500K $560K −$60K Projected to exceed budget Under budget $500K $470K +$30K Forecast surplus Re-baselined $580K $580K $0 New approved baseline - CPI = EV / AC = 100,000 / 130,000 = 0.769 (pārsniedz budžetu)
- EAC = BAC / CPI = 400,000 / 0.769 = $520,156
- VAC = BAC − EAC = 400,000 − 520,156 = −
Budget at Completion vs Estimate at Completion (BAC vs EAC)
The most common point of confusion in Earned Value Management is the relationship between Budget at Completion (BAC) and Estimate at Completion (EAC). They look similar, they both represent a "total project cost", but they behave in completely opposite ways.
BAC = the cost you planned before the project started. It is fixed.
EAC = the cost you currently forecast to finish. It changes as the project evolves.
Quick Comparison: BAC vs EAC
Property BAC (Budget at Completion) EAC (Estimate at Completion) Definition Total approved baseline budget Forecasted total project cost When set Once, at project baseline Recalculated throughout execution Changes? Only via formal re-baselining Yes — updated every reporting period Based on Planned estimates only Actual cost + performance indices Formula Σ (all work package budgets) BAC / CPI (most common of 4 formulas) PMBOK ref. 6th Ed. p.263 6th Ed. p.264–265 At Project Start: BAC = EAC
At the moment a project baseline is approved, BAC and EAC are identical. No work has been performed, no actual costs have been incurred, so the forecast equals the plan. As soon as execution begins and real data appears (AC, EV), EAC starts to diverge from BAC.
What is the difference between BAC and EAC?
The key distinction: BAC represents commitment — what was formally agreed with stakeholders. EAC represents reality — what the project is actually projected to cost based on observed performance.
Consider this example: a software project with BAC = $400,000.
- After 3 months: AC = $130,000, EV = $100,000 (25% complete)
- CPI = EV / AC = 100,000 / 130,000 = 0.769 (over budget)
- EAC = BAC / CPI = 400,000 / 0.769 = $520,156
- VAC = BAC − EAC = 400,000 − 520,156 = −$120,156 (projected overrun)
BAC is still $400,000. EAC is now $520,156. The $120,156 gap is what the project manager needs to explain and manage.
Can BAC change during a project?
Yes, but only through a formal process. BAC changes in two scenarios:
- Approved scope change — Additional work packages are added via change control, increasing (or decreasing) the authorized budget.
- Re-baselining — Senior management formally approves a new cost baseline, typically when the original BAC is no longer achievable and a fresh start is needed. This is a significant governance event.
Cost overruns alone NEVER change BAC. They are reflected in EAC and VAC instead.
What does it mean when EAC exceeds BAC?
When EAC exceeds BAC (VAC is negative), the project is projected to finish over budget. The difference represents the forecasted cost overrun. Project managers must report this to stakeholders and take corrective action to drive CPI closer to 1.0 — which reduces EAC.
Research cited in PMBOK shows that once CPI drops below 0.9, it rarely recovers significantly after the 20% completion mark. This makes early EAC forecasting critical.
When EAC is Below BAC
When EAC is less than BAC, VAC is positive — the project is forecast to finish under budget. This is favorable and represents a budget surplus.
The 4 EAC Formulas and How They Relate to BAC
All four PMBOK EAC formulas reference BAC:
EAC₁ = BAC / CPI ← typical performance continues (most common)
EAC₂ = AC + (BAC − EV) ← one-time variance; future at planned rate
EAC₃ = AC + (BAC − EV) / CPI ← sustained CPI impact (= EAC₁)
EAC₄ = AC + (BAC − EV) / (CPI × SPI) ← schedule pressure adds costThe relationship between BAC and each EAC determines VAC = BAC − EAC. The formula you choose reflects your assumption about future performance — but all four start from the same fixed BAC.
Summary Table
→ Calculate BAC, EAC and VAC Instantly 20,156 (prognozētais pārtēriņš)Situation BAC EAC VAC Meaning On track $500K $500K $0 On budget Cost overrun $500K $560K −$60K Projected to exceed budget Under budget $500K $470K +$30K Forecast surplus Re-baselined $580K $580K $0 New approved baseline
Šajā scenārijā oriģinālais budžets (BAC) joprojām ir stingri $400,000. Jums nav iedota papildu nauda. Tomēr jūsu prognoze (EAC) rāda, ka pabeigšanai būs nepieciešami $520,156. Jums būs jāpaskaidro vadībai un jāpārvalda šī −
Budget at Completion vs Estimate at Completion (BAC vs EAC)
The most common point of confusion in Earned Value Management is the relationship between Budget at Completion (BAC) and Estimate at Completion (EAC). They look similar, they both represent a "total project cost", but they behave in completely opposite ways.
BAC = the cost you planned before the project started. It is fixed.
EAC = the cost you currently forecast to finish. It changes as the project evolves.
Quick Comparison: BAC vs EAC
| Property | BAC (Budget at Completion) | EAC (Estimate at Completion) |
|---|---|---|
| Definition | Total approved baseline budget | Forecasted total project cost |
| When set | Once, at project baseline | Recalculated throughout execution |
| Changes? | Only via formal re-baselining | Yes — updated every reporting period |
| Based on | Planned estimates only | Actual cost + performance indices |
| Formula | Σ (all work package budgets) | BAC / CPI (most common of 4 formulas) |
| PMBOK ref. | 6th Ed. p.263 | 6th Ed. p.264–265 |
At Project Start: BAC = EAC
At the moment a project baseline is approved, BAC and EAC are identical. No work has been performed, no actual costs have been incurred, so the forecast equals the plan. As soon as execution begins and real data appears (AC, EV), EAC starts to diverge from BAC.
What is the difference between BAC and EAC?
The key distinction: BAC represents commitment — what was formally agreed with stakeholders. EAC represents reality — what the project is actually projected to cost based on observed performance.
Consider this example: a software project with BAC = $400,000.
- After 3 months: AC = $130,000, EV = $100,000 (25% complete)
- CPI = EV / AC = 100,000 / 130,000 = 0.769 (over budget)
- EAC = BAC / CPI = 400,000 / 0.769 = $520,156
- VAC = BAC − EAC = 400,000 − 520,156 = −$120,156 (projected overrun)
BAC is still $400,000. EAC is now $520,156. The $120,156 gap is what the project manager needs to explain and manage.
Can BAC change during a project?
Yes, but only through a formal process. BAC changes in two scenarios:
- Approved scope change — Additional work packages are added via change control, increasing (or decreasing) the authorized budget.
- Re-baselining — Senior management formally approves a new cost baseline, typically when the original BAC is no longer achievable and a fresh start is needed. This is a significant governance event.
Cost overruns alone NEVER change BAC. They are reflected in EAC and VAC instead.
What does it mean when EAC exceeds BAC?
When EAC exceeds BAC (VAC is negative), the project is projected to finish over budget. The difference represents the forecasted cost overrun. Project managers must report this to stakeholders and take corrective action to drive CPI closer to 1.0 — which reduces EAC.
Research cited in PMBOK shows that once CPI drops below 0.9, it rarely recovers significantly after the 20% completion mark. This makes early EAC forecasting critical.
When EAC is Below BAC
When EAC is less than BAC, VAC is positive — the project is forecast to finish under budget. This is favorable and represents a budget surplus.
The 4 EAC Formulas and How They Relate to BAC
All four PMBOK EAC formulas reference BAC:
EAC₂ = AC + (BAC − EV) ← one-time variance; future at planned rate
EAC₃ = AC + (BAC − EV) / CPI ← sustained CPI impact (= EAC₁)
EAC₄ = AC + (BAC − EV) / (CPI × SPI) ← schedule pressure adds cost
The relationship between BAC and each EAC determines VAC = BAC − EAC. The formula you choose reflects your assumption about future performance — but all four start from the same fixed BAC.
Summary Table
| Situation | BAC | EAC | VAC | Meaning |
|---|---|---|---|---|
| On track | $500K | $500K | $0 | On budget |
| Cost overrun | $500K | $560K | −$60K | Projected to exceed budget |
| Under budget | $500K | $470K | +$30K | Forecast surplus |
| Re-baselined | $580K | $580K | $0 | New approved baseline |
Vai BAC var mainīties projekta laikā?
Jā, bet tikai izmantojot formālu procesu. BAC mainās divos gadījumos:
- Apjoma izmaiņas: Klients pievieno jaunas prasības. Tas iet caur izmaiņu kontroli, palielinot (vai samazinot) apstiprināto budžetu.
- Bāzes līnijas pārskatīšana: Projekts ir tik ļoti novirzījies no kursa, ka sākotnējā bāzes līnija vairs nav jēgpilna, un vadība piekrīt noteikt jaunu bāzes līniju (reti, un parasti pēc liela vadības notikuma).
Tikai izmaksu pārtēriņš NEKAD nemaina BAC. Tā vietā tas tiek atspoguļots EAC un VAC.
Kā izvēlēties pareizo EAC formulu
Lai gan BAC ir tikai viena definīcija, PMBOK sniedz vairākus veidus, kā aprēķināt EAC, atkarībā no projekta apstākļiem:
1. Tipiska veiktspēja (EAC = BAC / CPI)
Izmantojiet, ja sagaidāt, ka pašreizējais CPI (labs vai slikts) saglabāsies tāds pats līdz projekta beigām. Šis ir noklusējuma aprēķins.
2. Vienreizēja novirze (EAC = AC + (BAC − EV))
Izmantojiet, ja iepriekšējās izmaksu problēmas bija vienreizējs notikums (piemēram, unikāla aparatūras kļūme), un jūs sagaidāt, ka atlikušais darbs noritēs atbilstoši sākotnējam budžetam.
3. CPI un SPI ietekme (EAC = AC + [(BAC − EV) / (CPI × SPI)])
Izmantojiet, ja projekts gan kavējas, GAN pārsniedz budžetu, un kavēšanās ietekmēs turpmākās izmaksas (piemēram, maksājot par virsstundām, lai panāktu iekavēto).
4. Augšupējs ETC novērtējums (EAC = AC + Bottom-up ETC)
Izmantojiet, ja sākotnējais novērtējums bija būtiski kļūdains un jums ir atkārtoti jānovērtē visi atlikušie darbi no nulles.
Kopsavilkums
Uztveriet to kā ceļojumu ar automašīnu. BAC ir naudas summa, ko plānojāt iztērēt degvielai pirms izbraukšanas. EAC ir summa, ko domājat iztērēt tagad, kad redzat, ka jūsu automašīna patērē vairāk degvielas, nekā gaidīts.
→ Izmēģiniet BAC kalkulatoru bez maksas