Project Post-Calculation: Tips & Best Practices

Aug 11, 2025 by Alexander Huber

According to the CHAOS Report 2020 by the Standish Group, only about 31% of IT/software projects are truly successful. 50% are considered challenging (deviations in budget, time, or scope), and 19% fail completely. (CDT)

Projects start with ambitious plans, but in the end, they’re often more expensive, take longer, or are less profitable than expected. The big question then is: “What happened?”

This is exactly where project post-calculation comes in. It’s a structured look back to compare planned vs. actual values, understand variances, and derive lessons learned for the future. Without solid project time tracking, however, it’s a shot in the dark.

What Is Project Post-Calculation?

A post-calculation is a managerial accounting method used to capture the actual project costs and achieved profit after project completion and compare them with the planned values.

Core Objectives of a Post-Calculation

Transparency: Show whether the project was profitable.
Variance analysis: Which phases or tasks required more resources than planned?
Learning instrument: Improve future estimates, costing methods, and proposal quality.
Management input: Data for pricing, margin calculation, and process optimization.

In a project context, post-calculation is far more than an accounting formality. It becomes a controlling tool that provides both operational and strategic value.

Why Project Time Tracking Is the Foundation

A post-calculation is only as good as the data it’s based on. For service providers, time = money.

No Transparency Without Time Data

If you don’t track how many hours developers, consultants, or project managers spent on which work package, the biggest cost drivers remain invisible.

Time tracking provides:

Objectivity: Facts instead of gut feel.
Granularity: Effort can be assigned to specific projects, clients, or tasks.
Completeness: Non-billable hours become visible.
Compliance: In many countries (EU, AT, DE), working time tracking is mandatory anyway.

A practical example from our experience: An IT company used to do post-calculation “in their heads” until we introduced project time tracking. Only then did it become visible that around 15% of hours were worked but never billed. That led to systematic margin loss. A classic case of revenue leakage.

Prerequisites for a Successful Post-Calculation

For post-calculation to deliver insights rather than just numbers, certain conditions must be met.

1. Clean and Detailed Project Structure

Projects should be broken down into work packages.
These serve as “containers” for time, costs, and external services.
Only then can variances be pinpointed precisely.

☝️ But beware: don’t get lost in excessive detail. The art lies in creating a project structure that’s precise enough for solid post-calculation but not too granular. If employees have to spend time hunting for the right work package, they’ll quickly find time tracking tedious. An elegant solution: only present each person with the work packages relevant to them. They see only the tasks they’re actually scheduled for and booking becomes much easier and faster.

2. Consistent Project Time Tracking

Daily booking (“same-day booking”) prevents memory errors.
Tools should minimize the effort required to record time.
Non-billable time must also be tracked (meetings, bug fixing, internal coordination).

🤔 Let’s be honest: many people don’t log time immediately because they’re deep in work or sprinting from meeting to meeting. This is where digital assistants help. Like the Activity Tracker from time cockpit. It automatically records which files, apps, or projects were worked on. Later, employees have a reliable memory aid and can submit accurate time with just a few clicks.

3. Complete Cost Capture

In addition to own labor, include external services, material, and travel costs.
Create transparency between price deviations vs. quantity deviations. In post-calculation it’s crucial not only to identify variances but also to understand their causes. A quantity variance arises when more hours or services are needed than planned for certain work packages. A price variance occurs when unit costs e.g. external hourly rates or license prices are higher than estimated. Only when both dimensions are considered separately can you draw the right conclusions and improve future estimates.

💡 While a time tracking system primarily captures own labor (work hours), a complete post-calculation often requires additional data sources. External services, material, or travel costs are usually recorded in ERPs, accounting solutions, or specialized reporting tools. Only the combination of these sources yields a full cost picture.

4. Defined Baseline and KPIs

A post-calculation is only as good as the comparison data defined at project start. That means clearly documenting plan values such as planned hour budgets per phase, expected cost types (own labor, external, travel), and planned milestones. This data form the baseline against which all actuals are later measured.

5. Regular Reviews Instead of a One-Off Wrap-Up

Successful organizations check continuously: run plan–actual comparisons weekly or monthly.
This turns post-calculation from a purely ex-post analysis into an early warning system.

🎯 For plan–actual comparisons to be meaningful, it’s critical that time is recorded promptly. If hours are entered weeks later, important details are lost and variances go unnoticed. Without up-to-date data, project control is like flying blind. Successful companies review weekly or monthly and use post-calculation not just at the end but as an ongoing early warning system.

6. Embed Lessons Learned in Your Culture

A post-calculation is only valuable if results don’t vanish into an archive but are actively used. Variances shouldn’t be seen as blame but as learning opportunities. An open discussion culture is key, where causes like estimation errors, unclear requirements, or external influences can be named honestly.

A project closure report documents these insights and derives concrete recommendations e.g, buffer rules, improved estimation methods, or clearer change request processes. This way, post-calculation becomes a continuous improvement tool that makes projects more predictable and profitable.

Step by Step: How a Post-Calculation Works

Step 1: Introduce Project Time Tracking

All team members should record their time regularly, ideally daily. Modern tools reduce effort significantly and ensure the data is complete and consistent.

Step 2: Set Up the Project Structure

A clean structure with clearly defined phases and work packages is the foundation of any post-calculation. Only if tasks and responsibilities are clearly assigned can variances later be identified precisely.

👉 Example: In an ERP rollout, define phases like “Requirements Analysis,” “Implementation,” “Testing,” and “Go-Live” and you’ll immediately see where most extra hours accrued.

Step 3: Capture Costs

In addition to internal hourly rates, include external services, travel expenses, or license fees in the post-calculation. Only when all cost types are captured do you get a complete picture of project reality.

👉 Example: In a cloud project for a client, consider not only developer hours but also external Microsoft Azure cost statements and travel expenses for workshops.

Step 4: Plan–Actual Comparison

Next, compare planned efforts with actual recorded time and costs. Variances can be identified early and documented systematically.

👉 Example: 120 hours were planned for testing; the QA team actually spent 180 hours. Post-calculation immediately flags an overload in testing.

Step 5: Root Cause Analysis

More important than merely noting a variance is asking “why.” Typical causes include estimation errors, unclear requirements (scope creep), or inefficient project workflows.

👉 Example: In an e-commerce project, many extra hours stemmed from short-notice change requests. The root cause was the absence of a proper change request process.

Step 6: Lessons Learned

Don’t let post-calculation results gather dust. Feed insights into future proposals and project methods so planning improves step by step.

👉 Example: After a data warehouse project, the team decides to always include a 20% buffer for data migration in future quotes, because this was repeatedly a source of variance.

Common Pitfalls in Post-Calculation

Incomplete time data: One of the biggest stumbling blocks is incomplete time data. If employees record hours only sporadically or retrospectively, you won’t get a reliable picture of actual effort. Post-calculation then rests on estimates and loses its value.
Project structure too coarse: One of the biggest stumbling blocks is incomplete time data. If employees record hours only sporadically or retrospectively, you won’t get a reliable picture of actual effort. Post-calculation then rests on estimates and loses its value.
No view of non-billable time: Another classic: ignoring non-billable hours. Internal coordination, meetings, or bug fixing add up and significantly affect profitability. If these hours aren’t captured and evaluated, the result looks artificially positive.
Post-calculation too late: Often, post-calculation is done only at project end. That makes it a pure retrospective with no steering effect. Successful companies, by contrast, run regular in-project reviews and use them as an early warning system.

Why Post-Calculation Matters Especially for IT Service Providers

High share of personnel costs: Especially in IT, post-calculation is essential because the largest cost block is personnel. Every hour not recorded or misassigned immediately distorts financial results.
Intense competitive pressure: Margins in IT services are often tight. Transparency around time and cost variances directly determines profit or loss.
High change dynamics: Agile methods, scope changes, and shifting requirements mean projects rarely follow the plan exactly. Without ongoing post-calculation, it’s easy to lose track.
Regulatory environment: Legal requirements also matter. In many countries, complete time tracking is mandatory. That makes it not only the foundation for post-calculation but also part of compliance and corporate governance.

Conclusion

A post-calculation of projects is far more than a “box-ticking exercise.” It determines profitability, planning certainty, and competitiveness. The most important prerequisite: a structured project time tracking setup that makes all relevant effort visible.

👉 Especially for IT service providers: If you plan projects once but never run post-calculations, you risk repeating the same mistakes. If you consistently track time, compare continuously, and capture learnings, you build a sustainable foundation for better margins and happier customers. This turns post-calculation from a rear-view mirror into a true steering instrument.