Program Manager, PPM&PMO Specialist.| Coppel, Mexico.Culiacán, Sinaloa, Mexico
Colleagues;
As we all know, planning is the foundation of a successful project, but we each have that one specific area where we struggle the most.
In my experience, creating the schedule (cronograma) is always the toughest part. Because our organization follows a strict Waterfall approach, my team and I can only change dates through a formal change request process. This puts a lot of pressure on me to achieve a very high level of precision and accuracy from day one.
I always set a high bar for myself because I see the schedule as a serious commitment to the team and the stakeholders. However, balancing that need for accuracy with the reality of project risks is a constant challenge.
What about you? Which part of the planning phase do you find the most difficult? Is it the budget, the risk register, the resource allocation, or something else?
I look forward to hearing your perspectives and learning from your experiences!
I think The most challenging part of project planning is accurate estimation under uncertainty. Time, cost, and scope are tightly linked, yet they’re usually defined with incomplete information. Scope evolves, risks (especially human and organizational ones) are underestimated, and productivity is often assumed rather than measured. This leads to optimistic schedules and budgets that only reveal their flaws late in the project, when corrections are costly.
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2 replies by Francisco Herrera and Kwiyuh Michael Wepngong
Jan 22, 2026 2:31 PM
Francisco Herrera
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Alaa Alnafori I agree with you: Estimation under uncertainty is precisely what makes planning so difficult!
In my environment, where we use a strict Waterfall approach, the pressure to commit to 'promised dates' based on incomplete information is a constant challenge. As you mentioned, when scope evolves or risks are underestimated, those early commitments become very hard to maintain. It is definitely a balancing act between being professional with our deadlines and staying realistic about the project's uncertainty Francisco.
Feb 13, 2026 2:36 AM
Kwiyuh Michael Wepngong
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Thanks Alaa. You are on point... The uncertainty factor that interplays between cost, scope and time are a serious challenge for PMs
I'll take a step back from a specific knowledge area to state that one of the toughest aspects of planning is to find the "sweet spot" of planning. In other words, figuring out the right point to make a commitment on scope, schedule, cost and so on and to avoid pressure from others (especially clients and sponsors) to do this prematurely and from the team to do it too late.
Kiron
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1 reply by Francisco Herrera
Jan 21, 2026 11:31 AM
Francisco Herrera
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Kiron I completely agree with your point. Finding that 'sweet spot' is indeed one of the most difficult parts of leadership.
In my current environment, I feel a lot of pressure because we work with a strict Waterfall approach. This means I have to commit to a schedule very early, and as you mentioned, sponsors expect high precision from the start.
It is a constant struggle to manage those expectations while knowing that the team needs more time to be accurate. Balancing the client's demand for a fixed date with the reality of project constraints is exactly where the 'pressure' you mentioned becomes a real challenge.
Thank you for sharing that perspective; it really resonates with my daily work! Francisco.
Program Manager, PPM&PMO Specialist.| Coppel, Mexico.Culiacán, Sinaloa, Mexico
Jan 21, 2026 7:06 AM
Replying to Kiron Bondale
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Francisco -
I'll take a step back from a specific knowledge area to state that one of the toughest aspects of planning is to find the "sweet spot" of planning. In other words, figuring out the right point to make a commitment on scope, schedule, cost and so on and to avoid pressure from others (especially clients and sponsors) to do this prematurely and from the team to do it too late.
Kiron
Kiron I completely agree with your point. Finding that 'sweet spot' is indeed one of the most difficult parts of leadership.
In my current environment, I feel a lot of pressure because we work with a strict Waterfall approach. This means I have to commit to a schedule very early, and as you mentioned, sponsors expect high precision from the start.
It is a constant struggle to manage those expectations while knowing that the team needs more time to be accurate. Balancing the client's demand for a fixed date with the reality of project constraints is exactly where the 'pressure' you mentioned becomes a real challenge.
Thank you for sharing that perspective; it really resonates with my daily work! Francisco. Saving Changes...
In my experience, one of the challenges are the limited resources (project team) available to execute the tasks in your timeline. Usually those limited resources are shared between several projects running at the same time. I will say people allocation is challenging throughout the entire project.
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1 reply by Francisco Herrera
Jan 23, 2026 1:53 PM
Francisco Herrera
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Quetzal Castro I definitely agree. Managing shared resources adds a layer of complexity to the schedule, especially when team members are split across multiple projects. This 'competition' for time makes it even harder to maintain the high level of precision required in a Waterfall environment. It's a constant challenge to keep the timeline realistic under those conditions. Francisco.
There are probably three big challenges related to planning that I've had to deal with multiple times in my career.
The first is helping leadership understand that effective planning and testing assumptions, done well, don't actually slow the project down. Maybe planning takes a little longer, but we're building the right thing. Why do we have time to do the work three times but it's not okay to spend a little more time on planning, do it once, and get it right the first time, faster than doing it three times?
The second challenge is part of the first, but also presents itself at other points during the project. Data. You don't need a data scientist (normally), but you often need data to validate your assumptions and make sure you're solving the right problem. You need the right data, preferably complete and accurate. If you're passing data between systems, you need the same fields to exist in both systems if you're not transforming it into something new, first. Data migrations 1) take longer than you think, 2) do need testing and validation, and 3) can affect and be affected by network bandwidth.
Third is getting people to estimate both their effort and the expected duration. Don't tell me that the task is going to take two hours of work, and leave it at that, if you can't start it for three days and you have to spread out the work over four days. Assuming you finish your other work on schedule and nothing new comes up.
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1 reply by Francisco Herrera
Feb 11, 2026 12:17 PM
Francisco Herrera
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Aaron Porter you are right, especially regarding your first point. It’s a common struggle to convince leadership that planning is an investment, not a delay. I always say: 'Measure twice, cut once.'
Also, your distinction between effort and duration is a game-changer. Many delays happen simply because people confuse the two. Without accurate data and clear estimations, even the best plan becomes unrealistic. Thank you for your participation! Francisco.
I think The most challenging part of project planning is accurate estimation under uncertainty. Time, cost, and scope are tightly linked, yet they’re usually defined with incomplete information. Scope evolves, risks (especially human and organizational ones) are underestimated, and productivity is often assumed rather than measured. This leads to optimistic schedules and budgets that only reveal their flaws late in the project, when corrections are costly.
Alaa Alnafori I agree with you: Estimation under uncertainty is precisely what makes planning so difficult!
In my environment, where we use a strict Waterfall approach, the pressure to commit to 'promised dates' based on incomplete information is a constant challenge. As you mentioned, when scope evolves or risks are underestimated, those early commitments become very hard to maintain. It is definitely a balancing act between being professional with our deadlines and staying realistic about the project's uncertainty Francisco. Saving Changes...
For me, the most difficult part of the planning phase is resource allocation. On paper, it looks straightforward: assign people with the right skills to the right activities. In reality, resources are rarely fully dedicated, priorities change, and availability is often optimistic at best. Much like your experience with the schedule, resource plans tend to assume a level of stability that simply doesn’t exist once execution begins. What makes it especially challenging is that resource constraints silently affect everything else:
They introduce hidden risks into the schedule They drive productivity assumptions that are hard to validate upfront They can invalidate a “perfect” plan without any formal change triggering early warning
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1 reply by Francisco Herrera
Jan 26, 2026 6:51 PM
Francisco Herrera
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Luis I completely relate to your points. I have also faced these same challenges where resource constraints 'silently' impact the entire plan. In my experience, even a perfect schedule becomes fragile when team availability is more optimistic than realistic. It is a constant struggle to balance a stable plan with the unpredictable nature of resource allocation. Francisco.
For me, the most challenging part is risk planning and assumptions validation early on. I can build a solid schedule and budget, but predicting how risks, dependencies, and stakeholder decisions will actually play out is never exact.
I find the real challenge is balancing optimism with realism, planning well enough to commit, while still leaving room for uncertainty without over-buffering the plan.
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1 reply by Francisco Herrera
Jan 27, 2026 12:09 PM
Francisco Herrera
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Syed Ashir Riaz That makes perfect sense. I agree that even the most solid schedule is only as good as the assumptions behind it. Validating those dependencies early on is key, but as you said, predicting human and organizational behavior is never an exact science. It’s definitely one of the most unpredictable parts of our job. Francisco.
Program Manager, PPM&PMO Specialist.| Coppel, Mexico.Culiacán, Sinaloa, Mexico
Jan 21, 2026 10:12 PM
Replying to Quetzal Castro
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In my experience, one of the challenges are the limited resources (project team) available to execute the tasks in your timeline. Usually those limited resources are shared between several projects running at the same time. I will say people allocation is challenging throughout the entire project.
Quetzal Castro I definitely agree. Managing shared resources adds a layer of complexity to the schedule, especially when team members are split across multiple projects. This 'competition' for time makes it even harder to maintain the high level of precision required in a Waterfall environment. It's a constant challenge to keep the timeline realistic under those conditions. Francisco. Saving Changes...
Luis BrancoCEO| Business Insight, Consultores de Gestão, LdªCarcavelos, Lisboa, Portugal
This question touches the real tension in project planning, not the textbook one.
From a practitioner’s perspective, the most challenging aspect of planning is rarely a single artefact such as the schedule or the budget. It is maintaining coherence between assumptions, commitments and uncertainty across all planning components.
The example of scheduling in a strict Waterfall environment illustrates this well. When dates become contractual commitments from day one, the core difficulty shifts away from technical scheduling and into decision-making under uncertainty combined with expectation management. In many cases, the plan freezes earlier than reality does.
The risk register is another area where this tension becomes visible. While teams are generally good at identifying risks, they are often much weaker at translating them into explicit buffers, decision thresholds and governance rules that protect the schedule and budget without immediately triggering formal change requests.
Resource allocation presents a similar challenge. On paper it appears deterministic. In practice, availability, focus and skill depth fluctuate, yet many plans continue to assume idealized capacity.
Experience shows that planning becomes hardest precisely at the point where teams stop modelling work and start modelling human and organizational behaviour. Precision is necessary, but false precision is dangerous. A plan needs to be accurate enough to guide action, and humble enough to acknowledge where prediction is not possible.
That balance, particularly in predictive environments, is where planning truly earns its name. Saving Changes...
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