The Definitive Guide to Learning Lessons in Project Management

There are various ways in which we learn lessons long after our project management training course has ended. During the course of a career in project management, no matter what field you’re in, it’s important to understand where these lessons come from, and how they can help us become a better project management. Here, we look at just a few ways in which these lessons come.

This guide was substantially re-written in May 2026

Learning from the past

Working in the project management field requires professional training or learning on the job but it also incorporates many of the skills we naturally use in real life which includes common sense. It is said that the definition of insanity is doing the same things over and over and expecting different results (Einstein) but human beings are hardwired to keep repeating the same patterns – something we need to be especially mindful of when we want and need each project to be a resounding success.

Unfortunately, for many projects success is not happening. Only 22% of projects are being successfully completed according to  the Conditions for Project Success APM Research Report. When it comes to being successful in terms of budget only 1 in 8 projects actually manages to achieve this according to the same report.

The break-through comes when we realise we do have the ability to break negative patterns but in order to do this we need to pause, reflect and be learning lessons at every stage of a project so as to create new winning formulas. This continual evaluation forms the building blocks of this career-field but everyone learns at different rates, so it is important to focus on learning from failures whilst still highlighting any gains. There is little point in continually berating yourself (or others) for falling short – no one is perfect and team morale needs to be kept at a high.

Modern project data helps reinforce how important reflective learning really can be. According to PMI’s Pulse of the Profession, 65% of all projects fail when it comes to meeting their original defined goals. One of the top reasons that is cited in this instance is the failure to apply lessons learned from previous work to current projects. Other research shows that only 23% of organisations have implemented a formal lessons-learned process that is consistently followed by project teams. This means that most teams are repeating mistakes that could be easily avoided year after year.

The consequences that come from not learning from mistakes made in the past are significant. Analysis has found that poorly managed lessons-learned processes can contribute directly to project overruns. Many organisations lose millions on an annual basis due to repeated planning errors, communication failures and risk blind-spots. This type of statistic highlights that learning from the past isn’t just a “nice to have”, it is a measurable driver when it comes to project success. When a project team documents insights, shares them openly, and applies them early in new projects, success rates can and will increase dramatically.

The big mistakes to avoid – and how to learn from them

Only 25% of construction projects are completed within 10% of the original deadline.

KPMG

Taking on your first projects as a new manager can feel like a rollercoaster of fear and excitement so it is important to learn how to enjoy the ride whilst retaining your focus (and composure!). Having others depend on you for their sense of direction whilst navigating endless distractions requires a multi-skilled approach and it is inevitable that mistakes will be made.

One of the biggest mistakes is allowing a project to mushroom out of control so it’s important to take it a step at a time and focus on what is in front of you. A journey needs to be completed in stages and those stages broken down into commensurate parts that can then be tackled effectively by your team. Perhaps the most important factor is that of time. Commit to a too-tight deadline and you basically commit yourself to failure before you’ve even had chance to get your project off the ground. There will always be setbacks or obstacles thrown in your path so it’s imperative to allow you and your team wriggle room.

Only 31% of construction projects are completed within 10% of their original budget.

KPMG

In the construction industry in particular, both time and cost overruns are not unusual. Data from KPMG indicates that only 25% of projects in the field of construction are completed within 10% of the original set deadline and only 31% are completed within 10% of their original budget. Larger projects typically take 20% longer to finish and can be up to a staggering 80% over budget. These types of projects, however, are often given deadlines that leave little contingency for common risks such as supply chain issues.

Mistakes new project managers often make

It is easy to see why many want to work in project management. A career where no two days are the same provides endless variety and a continual learning environment for those that possess the thirst for knowledge. However, it is widely understood that there are issues with the skills gap which can make it difficult to find team members.

The PMI Global Project Management Talent Gap Report indicates that for the period 2025 – 2035 the demand for global project talent is set to rise by 64% which would suggest that the demand for qualified project professionals significantly outweighs the current supply.

Communication is key

Those wishing to train or begin work as a project manager need to grasp the fact that communication always holds the key to success. Written documents and meetings are just as important as informal chats and all methods of communication need to be utilised effectively to keep the whole team on track. Missing data, failure to use online tools and not delegating tasks accordingly are some of the most basic errors made as well as a lack of attention to proper risk assessment and management.

Saying no

The art of saying no and leading fairly but assertively will keep a new manager in good stead from the very first day on the job. Being a yes man or woman will quickly see scope creep take over, as will the temptation to micro manage – you need your team to get to the finish line.

And remember that even if you reach chartered status – the excitement of continually proving yourself and learning lessons will still be there; nicely paired with the wisdom to avoid the mistakes so common on the first rungs of the career ladder.

Learning from the best business leaders

In project management there is always something new to learn whether it’s a project management qualification that will help kick-start your change of career, a software tool that runs the office more smoothly and of course; the most valuable insights can be gained from the very best in the field.

Use your skill set

Every business leader has a particular skill-set that can act as a template for your own success.  When we think of project management greats – a name that immediately comes to mind is Richard Branson who worked his way up to celebrity status from very humble beginnings. His formula is the art of delegation and as a people person it’s something he’s mastered very well.

Whilst Mary Barra (General Motors) may be less well known, her embodiment of a “people-first” leadership mindset emphasises the fact that the best ideas do not have to come from the top. Her formula empowers the diverse perspectives within her team, ensuring that every angle is considered when evaluating a project.

This is because communication and interpersonal relationship skills are paramount – after all – you will be working with people helping to pull and keep the strings of your project together. Knowing your team’s strengths and weaknesses and choosing the best man or woman for each job will ensure your project never unravels! Other leaders such as Bill Gates and Steve Jobs can help you to think out of the box and never quit – even when the going gets tough.

How to really learn lessons

Large construction projects are typically a staggering 80% over budget.

KPMG

It is really important for a project manager to always have their thinking cap on. You can read all the advice regarding learning from mistakes but unless you commit to putting it into practice you and your team are bound to stay stuck and speaking of team – remember the saying there is no I in team. The best way to prove yourself as a project manager is to lead from the front and champion the people working with you. Lack of communication is always at the heart of any project juddering to a halt simply because it’s the common thread linking everything together.

Across almost all sectors there is one thing that project professionals agree on and that is that communication is the single most important skill that team members can have when it comes to any project. The PMI Pulse of the Profession report suggests that between 68-71% of project professionals believe communication is the most important skill, with problems solving coming in a close second with 68-69% of those who have been involved in project management for under 10 years. This number is slightly lower for those who have been in the industry for longer.

Document and learn

An effective way of ensuring past mistakes are not repeated is to firstly capture and then document them alongside with the project plan – something many mangers avoid perhaps because they don’t actually want to be reminded of them. But acceptance IS the first step towards effective change followed by discussions and brain-storming to determine the best course of action accompanied by bullet notes about the when’s, why’s and how’s.

The difference between failure and success is how quickly you get back on track even if it feels like your project is literally being de-railed. Lessons learnt throughout your project management career can help you do this well.

Whilst you may have already undertaken some form of project management training the field is continually evolving, and this means that attending training face-to-face or live can be a good way of ensuring that you are up to date with any new theories and ways of thinking that can assist you in your role.