On the other hand, done wrong, this can turn your project into a disaster. Statistically, unreliable software estimation is one of the top ten reasons for failure in software projects around the world. A wrong or absent estimation can result in unpredictable expenses, impossible deadlines and overall despondency among the team. It can break the budget, and it can break morale.
However, having a right estimation does not always mean that your project will succeed. There are a lot of contributing factors towards that. But software estimation can definitely be a valuable tool to keep your budget and timeline in check.
The question is – how to actually do it. To use it properly, we need to have a clear understanding of what it is, what part it plays in software development and what running the estimation involves.
What is software estimation?
Software estimation is the strategy to forecast the amount of money, time and resources that might be required to complete a software project – whatever mode of software that is. Like all other estimations and forecasts out there, software estimation is not 100% accurate. A 5-10% error margin must be considered to make the estimation valuable. In software companies, four internal factors tend to influence these estimations – experience, techniques, tools and processes.
There are several pros of running software estimation, including –
- Better management of uncertain situations
- Necessary adjustments made to the project plan
- Developers’ opportunity to dive into the requirements and understand the project deeply
- Understanding and managing stakeholders’ expectations
How can you perform software estimation?
Estimates often are interpreted to be just about predicting time requirements. The problem with which is that humans are not great at predicting the amount of time needed to complete a task. Which means, estimating time and cost required for a project is not easy. Many factors need to be considered to make an accurate estimation.
- Number of team members
- Complexity and size of software
- Scope of software
- Experience level of team members
- Span of product documentation
- Your knowledge about the product
Starting software estimation
Step 1: Understand the project requirements
Step 2: Prepare scope of the project – accurately
Step 3: Break the project down into smaller chunks
Step 4: Create a project plan
By combining the knowledge of your technical team, business analyst and project manager, you can truly come up with the most efficient project plan.
Step 5: Make the project tech-savvy
Step 6: Select your software estimation technique
Estimation techniques
Bottom-up estimation
This estimation technique involves dividing the project into smaller chunks of work so that you can better estimate the time and resources required to complete each part. Estimating requirements for a big project can be difficult. Not only in terms of time, but also in terms of dependency. When you build an app, there are going to be many co-dependencies among the features and tasks in the project. Failing to estimate these dependencies beforehand can result in blockers that reduce your efficiency and lengthen your time-to-market.
To follow the bottom-up approach,
- First, divide the complex project into small chunks.
- Estimate the complexity of each chunk of tasks.
- Estimate the overall time to complete each chunk and, as a result, the whole project.
While doing this, try and keep in mind that the time requirement for each task should be estimated based on its complexity.
Once time estimations are made for each task, an estimated time is calculated for each phase of the project, and then for the whole project. As the estimated time is summed up from smaller to larger parts, this technique is called the bottom-up technique.
Comparative technique
If you have done a project quite similar to this one in the past, the analogy can be quite helpful making this estimation technique a good choice for you. Software development companies tend to prefer this model when information about the project is limited or insufficient.
PERT technique
This technique is great for limiting inflated estimates. It is a simple technique that can be done by individual team members and then compared to come up with the most effective estimate.
The PERT technique is also known as the three point technique as it requires estimations from three data points.
- Best scenario or optimistic estimation
- Worst scenario or pessimistic estimation
- Most-likely scenario or realistic estimation
These estimations are then used to calculate the final one where
Final estimation = (Optimistic estimation + 4*Realistic estimation + Pessimistic estimation)/6
These estimation techniques can give you a good idea of how much time and resources might be needed to complete a project successfully. However, in our projects, we add a 10% buffer that usually represents testing and project management.
Why should you perform a software estimation?
If you think it is unnecessary, think again. Because there is a very high chance that you will regret not investing in software estimation further down in your project. Software estimation processes can be overwhelming in the beginning, especially when you and your team have minimal experience running a project. However, with time, the skill grows and you, too, will be able to understand how to effectively and efficiently run a software estimation making your projects stronger and well-planned.
