Thursday, March 10, 2011

Estimation Basic Need, options Starting Part 1

As someone correctly point out you can’t control things which you can’t measure. Very true to it’s logical sense. In our software day to day life we need to measure our efforts to track, monitor & control. This thoughts lead me to create this write-up for everyone in IT age to control day to day professional life.

A Software product / projects are typically controlled by four major variables; time, requirements, resources (people, infrastructure/materials, and money), and risks. Unexpected changes in any of these variables will have an impact on an execution. Hence, making good estimates of time and resources required for a project is crucial. Underestimating project needs can cause major problems because there may not be enough time, money, infrastructure/materials, or people to complete the project. Overestimating needs can be very expensive for the organization because a decision may be made to defer the project because it is too expensive or the project is approved but other projects are "starved" because there is less to go around.

In my experience, making estimates of time and resources required for a project is usually a challenge for most project teams and project managers. It could be because they do not have experience doing estimates, they are unfamiliar with the technology being used or the business domain, requirements are unclear, there are dependencies on work being done by others, and so on. These can result in a situation akin to analysis paralysis as the team delays providing any estimates while they try to get a good handle on the requirements, dependencies, and issues. Alternatively, we will produce estimates that are usually highly optimistic as we have ignored items that need to be dealt with. How does one handle situations such as these?

Useful Estimation Techniques

Before we begin, we need to understand & categorize what types of estimates we can provide. Estimates can be roughly divided into these types:

Initial estimates/ Ballpark or order of magnitude: Here the estimate is probably an order of magnitude from the final figure. This can be within two or three times the actual value.

Rough estimates: Here the estimate is closer to the actual value. Ideally it will be about 50% to 100% off the actual value.

Fair estimates: This is a very good estimate. Ideally it will be about 25% to 50% off the actual value.

Deciding which of these three different estimates you can provide is crucial. Fair estimates are possible when you are very familiar with what needs to be done and you have done it many times before. This sort of estimate is possible when doing maintenance type work where the fixes are known, or one is adding well-understood functionality that has been done before. Rough estimates are possible when working with well-understood needs and one is familiar with domain and technology issues. In all other cases, the best we can hope for before we begin is order of magnitude estimates. Some may quibble than order of magnitude estimates are close to no estimate at all! However, they are very valuable because they give the organization and project team some idea of what the project is going to need in terms of time, resources, and money. It is better to know that something is going to take between two and six months to do rather than have no idea how much time it will take. In many cases, we may be able to give more detailed estimates for some items rather than others. For example, we may be able to provide a rough estimate of the infrastructure we need but only an order of magnitude estimate of the people and time needed.

For a given scenario let’s think it thru with a role of a well educated developer, whether any project manager planning for a smooth implementation of a plan or a project sponsor on whose decisions a project depends, you cannot escape from the fact that project estimation is essential to its success. In the first place, there are three basic requirements that a project must satisfy: schedule, budget, and quality. The need to work within these essential project boundaries poses a huge challenge to everyone in the central management team.

There are various aspects that affect project estimates, such as team skills and experience levels, available technology, use of full-time or part-time resources, project quality management, risks, iteration, development environment, requirements, and most of all, the level of commitment of all project members.

Moreover, project estimations do not need to be too complicated. There are tools, methodologies, and best practices that can help project management teams, from sponsors to project managers, agree on estimates and push development efforts forward. Some of these include the following:

Project estimates must be based on the application’s solution, scope and architecture. Making estimates based on an application’s architecture should give you a clear idea of the length of the entire development project phase. Moreover, an architecture-based estimation provides you a macro-level view of the resources needed to complete the project.

Project estimations should also come from the ground up. All estimates must add up, and estimating the collective efforts of the production teams that work on the application’s modules helps identify the number of in-house and outsourced consultants that you need to hire for the entire project, as well as have a clear idea of the collective man-hours required to code modules or finish all features of the application. Ground-up estimates are provided by project team members and do not necessarily match top-level estimates exactly. In this case, it is best to add a percentage of architecture-based estimates to give room to possible reworks, risks, and other events that may or may not be within the control of the project staff.

Do not forget modular estimates. Once you have a clear idea of the architecture, it becomes easier to identify the modules that make up the entirety of the application. Knowing the nature of these modules should help you identify which can be done in-house or onshore, or by an offshore development team. Moreover, given the location and team composition of each development team that works on a module, it becomes easier to identify the technical and financial resources needed to work on the codes.

Development language matters. Whether the development language is Java, .Net, C++ or any other popular language used by software engineers, team that will be hired for the project must be knowledgeable in it. Some development efforts require higher skills in these languages, while some only need basic functional knowledge, and the levels of specialization in any of these languages have corresponding rates. Most of the time, the chosen development language depends on the chosen platform, and certain platforms run on specialized hardware.

You cannot promise upper management dramatic costs from offshoring. While there are greater savings from having development work done by offshore teams composed of workers whose rates are significantly lower from onshore staff, you must consider communication, knowledge transfer, technical set-up, and software installation costs in your financial estimates. Estimating costs is often more about managing expectations, but as the project matures, it should be clearer whether the money spent on it was money that was spent well.

Project estimation software and tools help identify “what-if” scenarios. Over the years, project managers have devised ways to automate project schedule, framework, cost, and staffing estimates. Some estimation applications also have sample historical data or models based on real-world examples. If your business has a lot in common with the samples in the estimation tool, it can help you identify what-if scenarios and in turn include risks, buffers, and iteration estimates.

Price break-down helps in prioritization. Breaking down the total cost of the project helps management decide which parts of a system should be prioritized, delayed, or even cancel. Estimating costs for a new project may not be easy, but project sponsors and managers must be able to know and agree on the breakdown of costs of development, technical requirements, and overhead.

These are some guide lines mentioned to understand the need for estimation & take it as part of daily life to get more control over all software process.

Feel free to reach me at ravindrapande@gmail.com to share thoughts & suggestions.

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