PEOPLE-RELATED MISTAKES 

Wishful thinking 

Being too optimistic (about risks and schedules). For instance, a team sets an extremely tight deadline that is impossible to achieve, therefore the promises to the client cannot be fulfilled and the project is left behind schedule.  

Another frequent mistake is to avoid task estimation due to the fact that they are simple tasks. Developers and QA could forget to perform those tasks or they could take longer than expected. 

Adding resources to a project that is behind schedule 

Sometimes when a project is behind schedule, the easiest and fastest solution seems to be adding more people to increase work speed but that’s not the result. On the contrary, what happens is that it takes away productivity since they need to be explained how things work, and the learning curve for how the team/tools/business work is not taken into account in the estimation. Adding a developer is not just plug and play. 

PROCESS-RELATED MISTAKES  

Insufficient risk management 

Failure to manage risk is one of the most common classic mistakes. When a risk arises, a low level of knowledge along with a lack of planning to manage it, can cause a high impact on the development process in terms of time, cost or quality. 

Eliminating necessary tasks 

Due to lack of time or poor team commitment to their tasks, it is really common to eliminate or reduce quality by discarding necessary tasks such as testing or documentation. Maybe these tasks don’t seem important at the beginning, but they are essential in order to keep high-level quality standards. 

PRODUCT-RELATED MISTAKES 

Requirements gold plating 

Some projects have from their inception more requirements than they really need. It is common practice to believe the customer will be delighted to see additional or more polished features, and the project manager or developers work on that rather than what was asked for or expected. The client might be disappointed by the results, and the extra effort by the developer might be in vain. 

Developer gold plating 

New technologies come with the promise of new features, better quality products, easy-to-write syntax and better performance. Developers are fascinated by them and are sometimes anxious to try them out. The effort required to design, implement, test, document, and support features that are not required lengthens the schedule and those new characteristics are not really necessary for the product. 

TECHNOLOGY-RELATED MISTAKES 

Silver bullet syndrome 

Changes in technologies and processes without justification. There is too much confidence that new technology, methodology, language, platform, etc. will solve planning problems. 

Tools switching in the middle of a project 

Sometimes it can make sense to gradually upgrade within the same product line. But switching to a totally new tool or technology implies a learning curve, rework, and inevitable mistakes that usually cancel out any benefit when you are halfway through a project.