Project Cost Managementإدارة تكلفة المشروع
مقدمة الفصل
ماذا ستتعلم في هذا الفصل
- Discuss the project cost management processes.
- Understand the processes involved in cost budgeting and preparing a cost estimate and budget for an information technology project.
- Discuss different types of cost estimates and methods for preparing them.
- Understand the benefits of earned value management.
أقسام الفصل
- 1Cost and the cost management processesالتكلفة وعمليات إدارتها
- 2Estimating costsتقدير التكاليف
- 3Determining the budgetتحديد الميزانية
- 4Controlling costs and earned value managementالتحكم في التكلفة وإدارة القيمة المكتسبة
تلميح: استخدم أسهم لوحة المفاتيح للتنقل بين الشرائح.
Cost and project cost managementالتكلفة وإدارتها
Cost and the cost management processes
| Initiating | Planning | Executing | Monitoring & Control | Closing |
|---|---|---|---|---|
| — | Plan cost management, estimate costs, determine budget | لا تذكر الشرائح شيئًا هنا. | Control costs | لا تذكر الشرائح شيئًا هنا. |
Something given up in exchange. Costs are usually measured in monetary units like dollars.
Includes the processes required to ensure that the project is completed within an approved budget.
Cost management processesعمليات إدارة التكلفة
| Processالعملية | Descriptionالوصف | Outputالمخرج |
|---|---|---|
| 1. Planning cost management | Determining the policies, procedures, and documentation that will be used for planning, executing, and controlling project cost. | Cost management plan |
| 2. Estimating costs | Developing an approximation or estimate of the costs of the resources needed to complete a project. |
|
| 3. Determining the budget | Allocating the overall cost estimate to individual work items to establish a baseline for measuring performance. |
|
| 4. Controlling costs |
| لا تذكر الشرائح شيئًا هنا. |
1. Planning cost managementتخطيط إدارة التكلفة
Cost and the cost management processes
Determining the policies, procedures, and documentation that will be used for planning, executing, and controlling project cost.
| Componentالمكوّن | From the slidesمن الشرائح |
|---|---|
| Level of accuracy and units of measure |
|
| Organizational procedure links | The WBS component used for project cost accounting is the control account (CA), often assigned a unique code used in the organization's accounting system. |
| Control thresholds | A specified amount of variation allowed before action needs to be taken, such as ±10 percent of the baseline cost. |
| Rules of performance measurement | If the project uses earned value management (EVM), the plan defines measurement rules, such as how often actual costs will be tracked and to what level of detail. |
| Reporting formats | Describe the format and frequency of cost reports required for the project. |
| Process descriptions | Describe how to perform all the cost management processes. |
2. Estimating costs: types of estimatesأنواع تقديرات التكلفة
Project managers must take cost estimates seriously if they want to complete projects within budget constraints.
| Type of estimateالنوع | When doneمتى | Why doneلماذا | How accurateالدقة |
|---|---|---|---|
| Rough order of magnitude (ROM) | Very early in the project life cycle, often 3–5 years before project completion | Provides estimate of cost for selection decisions | −50% to +100% |
| Budgetary | Early, 1–2 years out | Puts dollars in the budget plans | −10% to +25% |
| Definitive | Later in the project, less than 1 year out | Provides details for purchases, estimates actual costs | −5% to +10% |
Estimate ranges: worked exampleمثال على نطاقات التقدير
Estimating costs
المسألة
The actual cost range for a project estimated at $120,500, for each type of estimate.
خطوات الحل
- ROM (−50% to +100%): 0.5 × 120,500 = 60,250 → 120,500 − 60,250 = 60,250; 1 × 120,500 = 120,500 → 120,500 + 120,500 = 241,000
- Budgetary (−10% to +25%): 0.1 × 120,500 = 12,050 → 108,450; 0.25 × 120,500 = 30,125 → 150,625
- Definitive (−5% to +10%): 0.05 × 120,500 = 6025 → 114,475; 0.1 × 120,500 = 12,050 → 132,550
النتيجة
ROM: $60,250 to $241,000 · Budgetary: $108,450 to $150,625 · Definitive: $114,475 to $132,550
Cost estimating toolsأدوات تقدير التكلفة
Estimating costs
تذكّر كل أداة ثم اكشف تعريفها.
- 1Analogous or top-down estimates
Use the actual cost of a previous, similar project as the basis for estimating the cost of the current project.
- 2Bottom-up estimates
Involve estimating individual work items or activities and summing them to get a project total.
- 3Parametric modeling
Uses project characteristics (parameters) in a mathematical model to estimate project costs.
Slide 24 shows an example cost estimate (Surveyor Pro project): WBS items with units, cost per unit and subtotals, level-2 totals and percentages, including reserves of 20% of the total estimate; total project cost estimate $1,521,240.
سؤال سريع
Estimating costs
3. Determining the budgetتحديد الميزانية
Allocating the project cost estimate to individual work items over time.
Inputs:
- The WBS — defines the work items.
- Cost management plan.
- Scope baseline.
- Activity cost estimates.
- Project schedule.
- Resource calendars.
To produce a cost baseline for measuring project performance and project funding requirements.
A time-phased budget that project managers use to measure and monitor cost performance. Slide 29 shows the Surveyor Pro cost baseline: each WBS item's cost spread over months 1–12, totalling $1,521,240.
4. Controlling costs and earned value managementالتحكم في التكلفة والقيمة المكتسبة
Project cost control includes:
- Monitoring cost performance.
- Ensuring that only appropriate project changes are included in a revised cost baseline.
- Informing project stakeholders of authorized changes to the project that will affect costs.
- Tools such as earned value management (EVM).
A project performance measurement technique that integrates scope, time, and cost data. Given a cost baseline, the team enters actual information and compares it to the baseline (original plan plus approved changes).
ثلاث قيم لكل نشاط
- Planned value (PV)
- Actual cost (AC)
- Earned value (EV)
PV, AC, EV and rate of performanceالقيم الثلاث ومعدل الأداء
Controlling costs and earned value management
Also called the budget: the portion of the approved total cost estimate planned to be spent on an activity during a given period. PV = BAC × percentage of work planned.
The total of direct and indirect costs incurred in accomplishing work on an activity during a given period.
An estimate of the value of the physical work actually completed, based on the original planned costs and the rate at which the team is completing work.
The ratio of actual work completed to the percentage of work planned to have been completed. RP = % of actual work completed / % of work planned.
Earned value formulasصيغ القيمة المكتسبة
Controlling costs and earned value management
| Termالمصطلح | Formulaالصيغة | How to read itالتفسير |
|---|---|---|
| Earned value (EV) | EV = original PV × RP, or EV = BAC × (% of actual work completed) | “Earned value is the king.” |
| Cost variance (CV) | CV = EV − AC |
|
| Schedule variance (SV) | SV = EV − PV |
|
| Cost performance index (CPI) | CPI = EV / AC |
|
| Schedule performance index (SPI) | SPI = EV / PV |
|
| Estimate at completion (EAC) | EAC = BAC / CPI | Estimated cost of completing the project based on performance to date. |
Similarly, the SPI can be used to calculate an estimated time to complete the project: original time estimate / SPI.
سؤال سريع
Controlling costs and earned value management
EVM example: software development budgetمثال: ميزانية تطوير برمجيات
Controlling costs and earned value management
المسألة
A project has an $800,000 software development budget; two teams will work six months for a total of 10,000 hours. After more than 2 months, the team should be done with 38% of the work. The project is 40% complete while 50% of the budget has been used. Perform EV analysis.
المعطيات
- BAC
- $800,000
- AC
- $400,000 (50% budget used)
خطوات الحل
- PV = BAC × (% of work planned) = 800,000 × 0.38 = $304,000
- EV = BAC × (% of actual work completed) = 800,000 × 0.40 = $320,000 (or RP = 0.40 / 0.38; EV = RP × PV = $320,000)
- CV = EV − AC = 320,000 − 400,000 = −80,000
- CPI = EV / AC = 320,000 / 400,000 = 0.8
- SV = EV − PV = 320,000 − 304,000 = 16,000
- SPI = EV / PV = 320,000 / 304,000 = 1.05
النتيجة
Since CPI is less than 1, the project is over budget; and since SPI is more than 1, the project is ahead of schedule.
More EVM examplesأمثلة أخرى على القيمة المكتسبة
Controlling costs and earned value management
| Example A (slides 47–48) | Example B (slides 49–50) | |
|---|---|---|
| Given |
|
|
| EV | 42,461 × 0.94204 = 40,000 | 10,000 × 50% = 5,000 |
| CV | 40,000 − 48,923 = −8,923 | 5,000 − 15,000 = −10,000 |
| SV | 40,000 − 42,461 = −2,461 | 5,000 − 10,000 = −5,000 |
| CPI | 40,000 / 48,923 = 81.761% | 5,000 / 15,000 = 33% |
| SPI | 40,000 / 42,461 = 94.204% | 5,000 / 10,000 = 50% |
| EAC | 100,000 / 0.81761 = 122,308 | 100,000 / 0.33 = 303,030 |
المسألة
Slides 61–62: EV = $20,000, AC = $25,000, PV = $23,000, BAC = $120,000, planned time 12 months.
خطوات الحل
- CV = 20,000 − 25,000 = −$5,000; SV = 20,000 − 23,000 = −$3,000
- CPI = 20,000 / 25,000 = 80%; SPI = 20,000 / 23,000 = 87%
- EAC = BAC / CPI = 120,000 / 80% = $150,000
- Estimated time to complete = 12 months / 87% = 13.80 months
النتيجة
Behind schedule (negative SV, SPI 87%) and over budget (CPI 80%); EAC $150,000 — $30,000 over, worse than planned; about 13.80 months to complete.
The earned value chartمخطط القيمة المكتسبة
Controlling costs and earned value management
- Planned value (PV): the cumulative planned amounts for all activities by month; the PV line extends for the estimated length of the project and ends at the BAC point.
- Actual cost (AC): the cumulative actual amounts for all activities by month.
- Earned value (EV): the cumulative earned value amounts for all activities by month.
- Budget at completion (BAC): the original total budget — $100,000 in the example, plotted at the original time estimate of 12 months.
- Estimate at completion (EAC): $122,308 in the example (BAC / CPI = 100,000 / 81.761%), plotted at the estimated time to complete of 12.74 months (12 / 94.204%).
An EAC point above and to the right of the BAC point means the project is projected to cost more and take longer than planned (slide 57).
| Slide | Top | Middle | Bottom | Label on slide 56 |
|---|---|---|---|---|
| 52 | Planned cost | Actual cost | Earned Value | Late and over-spent |
| 53 | Earned Value | Planned cost | Actual cost | Early and under-spent |
| 54 | Actual cost | Earned Value | Planned cost | Early and over-spent |
| 55 | Planned cost | Earned Value | Actual cost | Late and under-spent |
سؤال سريع
Controlling costs and earned value management
الخلاصة
أنهيت الدرس
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