Showing posts with label parametric estimation. Show all posts
Showing posts with label parametric estimation. Show all posts

Friday, April 26, 2013

Estimation Techniques and Cost Benefit Analysis


Though Estimation Techniques and Cost Benefit Analysis are not explicitly listed down as tools and techniques for this process, we need to be aware of them to apply the other actual tools and techniques for the process. That is the reason why we have this chapter here amidst all the tools and techniques for this monitor and control risks process.

Estimation Techniques:

As part of examining project performance information and monitoring & controlling risks, we will be using/evaluating many estimating techniques and we need to know them at least at a high level in order to assess the project performance as well as to assess the status of the risks. The following are some of the major estimation techniques that we may use in our projects:

1. Analogous Estimating – This is a technique where we estimate the cost of the current project by applying our expert judgment on the actual costs from previous projects. This is a fast and cheap estimation technique but is not very accurate because the parameters considered while estimating the old project may or may not be applicable for our current project and so the estimates may not be accurate. This technique is typically used when resources to do the estimation are low and we are only looking for a high-level or ball-park kind of estimate.
2. Bottom-Up Estimating – This is a technique where we estimate the individual work packages (From the Work Breakdown Structure) and then the individual numbers are rolled up to the project level for the overall estimate. This kind of estimation is time consuming is much more accurate when compared to the Analogous technique. This technique is typically used when we have abundant budget and time to take up estimation at a detailed level.
3. Parametric Estimating – This is the third technique where we use historic data along with other information to arrive at the estimates for our project. For ex: If one person can build a wall in 10 days alone, how long would it take for 3 people to do? This technique is typically used for repetitive activity where the parameters affecting the work and estimate are well known.


Cost Benefit Analysis

Cost benefit analysis is a common technique that we apply at various stages in the lifecycle of our project. It compares the cost of producing a service, product or result to the benefits that the organization (doing/creating it) receives as a result of it.

For ex: If I were to own a supermarket. If the cost of buying a product is X and the cost of keeping it in my store, taking care of it etc. is Y then, the price at which I sell it to you must be greater than X+Y otherwise there will be no benefit (profit) in selling that product.

Cost benefit analysis must also consider initial costs, marketing and advertising expenses, maintenance and support of the product/service for cost benefit analysis. If I were to consider only the purchase and selling price to do cost benefit analysis of my items and ignore my store rent, electricity bill, worker wages etc., then even if I sell my products at a price greater than the cost I bought it, I might end up losing money.

Trivia:
In real life cost benefit analysis is used in various places. For ex: if the project is facing an issue and we are to implement a fix, we need to understand the cost of the fix, the benefits we gain out of implementing the fix before we go ahead. If the benefits I gain are more than the cost I incur then the fix is beneficial and it makes sense in going ahead with the fix.


Prev: Variance & Trend Analysis

Next: Technical Performance Measurement & Status Meetings

Friday, July 15, 2011

Points to Remember: Project Cost Management

Analogous Estimating is sometimes called “Top-Down Estimating”. Take a minute and think about why it would be called “top-down.” When you’re doing bottomup estimating, first you break it down into pieces, estimate each piece, and add them up. Analogous estimation is the opposite: you start with the whole project (without breaking it up at all), find other projects that were like it, and use those projects to come up with a new estimate.

Cost of Quality is how much money it takes to do the project right.

Benefit cost ratio (BCR): This is the amount of money a project is going to make versus how much it will cost to build it. Generally, if the benefit is higher than the cost, the project is a good investment.

Net present value (NPV): This is the actual value at a given time of the project minus all of the costs associated with it. This includes the time it takes to build it and labor as well as materials. People calculate this number to see if it’s worth doing a project. Money you’ll get in three years isn’t worth as much to you as money you’re getting today. NPV takes the “time value” of money into consideration, so you can pick the project with the best value in today’s dollars.

Just because you plan out a budget in your Cost Performance Baseline, that doesn’t mean your project is 100% guaranteed to fall inside that budget. It’s common for a company to have a standard policy for keeping a management reserve to cover unexpected, unplanned costs. When you need to get your project funded, that funding has to cover both the budget in your Cost Performance Baseline and the management reserve.

Parametric Estimation is used in Estimate Costs and Determine Budget.

Cost Aggregation is rolling up costs from the work package level to the control account level so that the numbers can be followed down through the WBS hierarchy.

Control Accounts are highlevel WBS items that are used to track cost estimates. They do not represent activities or work packages. They represent the cost of the work packages and activities that appear under them in the WBS

The main output of Estimate Costs is the Activity Cost Estimate and the Basis of Cost Estimate. The main output of Determine Budget is the Cost Performance Baseline and Project Funding Requirements.

You will get questions on the exam asking you to select between projects using Net Present Value (NPV) or Benefit Cost Ratio (BCR). Always choose the project with the biggest NPV or BCR!

Lifecycle Costing means estimating the money it will take to support your product or service when it has been released.

Rough Order of Magnitude Estimation is estimating with very little accuracy at the beginning of a project and then refining the estimate over time. It’s got a range of –50% to +50%.

If the SPI is below 1, then your project is behind schedule. But if you see a CPI under 1, your project is over budget! SPI and CPI are just ratios! If SPI is really close to 1, then SV will be really close to zero—and it means that my project is going as planned! And when your CPI is really close to 1, it means that every dollar your sponsor’s spending on the project is earning just about a dollar in value.


Points to Remember - Other Topics:

Introduction to Projects & Project Management
Relationship Between Knowledge Areas & Process Groups
Project Integration Management
Project Scope Management
Project Time Management
Project Quality Management
Human Resource Management
Project Communication Management
Project Risk Management
Project Procurement Management
Ethics & Professional Responsibility
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