Estimation is a common activity, especially in engineering and business. Professionals have to
estimate the project duration, budget requirement, and risk. Several tools and methods are
available to make sure these estimations are accurate. However, it is difficult to make a perfectly
accurate estimate even using project management tools and techniques. Estimation errors could
be manifested as overestimation or underestimation. Hence, the question would be is it worse to
over or underestimate?
Overestimation happens when the professional has a negative experience in the past with a
similar project (Griffin, 2015). Overestimation has many disadvantages that project managers
should need to consider. One of the problems is that if the project is overestimated, then the work
will inflate and fill the presented time. For instance, a project that could be completed within 5
months but given 8 months will end up taking 8 months. This is called Parkinson's Law and it
might push managers to intentionally underestimate the project (The Economist, 2020).
Another issue is that if a project manager gives too much time for his team to complete a project,
they will procrastinate. This is created because the project team will think the time given to
complete the project is more than necessary hence they could start the project at a later time.
Since the project team procrastinates they may not finish the project within the deadline and the
quality of the work is compromised. This issue is known as Goldratt's "Student Syndrome"
(Goldratt 1997).
Underestimation is caused when a professional doesn't have the necessary experience or
knowledge and becomes too optimistic (Griffin, 2015). Underestimation creates several
problems and could undermine successful project completion. One of the issues with
underestimation is that crucial project activities like planning, methodology preparation, and
team composition will not be given due attention. Consequently, planning errors, incorrect
methodologies, use of smaller teams, and other issues will affect project execution. If multiple
teams are working on a project it would be difficult for teams to integrate their work.
Furthermore, it creates stress on the project team to finish with the tight deadline that is based on
erroneous estimates. This stress added to the faster pace will result in the team making more
errors. Additionally, if the project is delayed a little the team will focus on unnecessary activities
like holding a meeting with upper management and client, frequent rescheduling, and demo
estimate the project duration, budget requirement, and risk. Several tools and methods are
available to make sure these estimations are accurate. However, it is difficult to make a perfectly
accurate estimate even using project management tools and techniques. Estimation errors could
be manifested as overestimation or underestimation. Hence, the question would be is it worse to
over or underestimate?
Overestimation happens when the professional has a negative experience in the past with a
similar project (Griffin, 2015). Overestimation has many disadvantages that project managers
should need to consider. One of the problems is that if the project is overestimated, then the work
will inflate and fill the presented time. For instance, a project that could be completed within 5
months but given 8 months will end up taking 8 months. This is called Parkinson's Law and it
might push managers to intentionally underestimate the project (The Economist, 2020).
Another issue is that if a project manager gives too much time for his team to complete a project,
they will procrastinate. This is created because the project team will think the time given to
complete the project is more than necessary hence they could start the project at a later time.
Since the project team procrastinates they may not finish the project within the deadline and the
quality of the work is compromised. This issue is known as Goldratt's "Student Syndrome"
(Goldratt 1997).
Underestimation is caused when a professional doesn't have the necessary experience or
knowledge and becomes too optimistic (Griffin, 2015). Underestimation creates several
problems and could undermine successful project completion. One of the issues with
underestimation is that crucial project activities like planning, methodology preparation, and
team composition will not be given due attention. Consequently, planning errors, incorrect
methodologies, use of smaller teams, and other issues will affect project execution. If multiple
teams are working on a project it would be difficult for teams to integrate their work.
Furthermore, it creates stress on the project team to finish with the tight deadline that is based on
erroneous estimates. This stress added to the faster pace will result in the team making more
errors. Additionally, if the project is delayed a little the team will focus on unnecessary activities
like holding a meeting with upper management and client, frequent rescheduling, and demo
