You want to estimate your software, but AppStore is just offering planning poker? Not any longer!
weEstimate combines the power of several software estimate methods into one comprehensive tool now available on your iPhone and iPod Touch. weEstimate allows you to estimate the effort, schedule and team size of IT and software projects.
How much effort and time do you need to put in your product? These are the important business factors that you and your customers are interested in. With weEstimate, you have all the answers right in your hands, anytime you need them.
weEstimate is a mobile version of the DAGσPERT estimate method developed by Sven Schweiger, CSS GmbH. A number of statistical principles are used to improve the total results compared to individual estimates. weEstimate was created as you sometimes have to literally “hunt down” your busy experts to get their estimate. When you finally get hold of them, there is usually no notebook in sight. But now you can create the tasks to be estimated on your iPhone and follow your expert into the kitchen or on the subway to get his or her opinion. Afterwards, the expert’s opinion can be transferred into the DAGσPERT estimation tool or it can be used as an independent estimate (download the free Microsoft Excel Version for group estimation at http://www.css-web.net/weEstimate).
- Create a new project
- Create tasks based on your specification: they have to cover the whole requirement range of the project to be estimated.
- Add all tasks to the task list. With the “Add” button you can easily add multiple tasks.
- Estimate the optimistic, realistic and pessimistic effort for each task. Choose the confidence level in % that represents, in your opinion, the probability of the real effort lying between the optimistic and pessimistic estimated values. A value under 99% will be shown as a raincloud in the overview.
- Add any noteworthy assumptions, risks, conditions or thoughts about the task in its comments field. The text will then be shown in the task list.
- When you are done with the estimation, open the “Results” view. It shows the total effort, optimal schedule and team size. The total effort is displayed in abstract person months: One person day equals 8 hours and one person month equals 20 person days. The schedule by rule of thumb applies for small projects (< 3 person months). The team should consist of max. 2 people. The schedule by impossible zone applies for medium and large projects and shows the minimal reasonable schedule and the matching team size. The schedule by basic equation applies for medium and large projects and shows the optimal schedule with the matching team size for an efficiently working team.
You can also estimate User Stories instead of Tasks if you use an agile development process. The weighting of the 3 values follows the classic PERT formula: (1*optimistic + 4*realistic + 1*pessimistic) / 6. Consider the following to ideally profit from the advantages of the DAGσPERT method:
- Formulate independent tasks: at least 10 tasks, 20 to 30 or more would be better (law of large numbers).
- There should be an average probability of 50% that you are under- or overestimating.
- Always choose realistic ranges.
- Only reduce your confidence level if it is reasonable to have a small range but some conditions exist under which the range does not apply. Document these conditions in the comments field.
- Narrow ranges and a high confidence level of the individual estimates will lead to a narrow range of results. This is either due to an extraordinary confidence of the estimating person (e.g. good reference projects) or too narrow ranges.
- Large ranges and a low confidence level of the individual estimates will lead to a wide range of results. This is often due to insecurity of the estimating person, e.g. because of unknown technologies, unclear specs, an estimate early in the project’s life cycle etc.