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Microsoft Project – A Glossary of Useful Terminology
By John Caulfield

The purpose of this article is to go through the main components and terms used in Microsoft Project and make them easier to understand. Project planners speak in a short hand that often excludes even computer literate individuals.

Project software and project management is very jargon laden this article will attempt to simply key project jargon for a new user. I for one have seen a dozen people sitting around a project plan discussing whether the new WBS might help the variance between the baseline plan and the project actual; only the project planner who was talking really knew what was going on.

What is a Project?

A project is any discrete set of interconnecting task with a defined start and end date. For example moving an office from location A to B would have a defined start date and a finish date culminating in a final launch party.

What are Tasks?

A task is any piece of work requiring effort. For example moving offices might require 4 hours of work effort.


Work and duration is not always the same thing. Monday to Friday I may have a five day task in duration writing a report but my intention is too only spend 50% of my time (work effort) on it.


Some tasks have no duration. Milestone tasks have zero duration. Let’s say that during a project moving an office from A to B a decision needs to be made between two similar sites. This meeting to decide the location would be described as a stage or milestone. Milestone tasks are displayed by default in MS Project with a diamond shape.

Linking Tasks

Everyone understands the concept that one task finishes; let’s say distributing boxes and the next one begins packing files. This is a linear of the world. The reverse is also true: one task cannot finish until another has begun. For example the canary down the coal mine cannot retire until the new air monitoring system is up and running. It is also possible that two tasks could start at the same time. In the new offices one tradesman could be laying carpet tiles in the same room at the same time as a painter tackling the ceiling. Similarly two tasks could have a finish to finish relationship: packing the furniture and computer might have a finish to finish relationship with each other in readiness for the next task of moving everything to the new office. A final possibility might be that two tasks have no logical relationship with each other but just need to be independently completed before the project is completed.

Format Time-scale

If a hospital was creating a template for the perfect heart bypass operation they would be working in hours and minutes but if London Underground were replacing an escalator they would be working in day, weeks and months.

Network Diagram

It is possible to view your project plan in many ways: one is a network diagram which is a flow diagram to show how the tasks relate to each other.

Gantt chart

This shows the task names on the left hand side of the screen and displays the tasks as bars on the right hand side underneath a time scale. Gantt charts were initially named after a planner called Henry Laurence Gantt who worked as a mechanical engineer (famous for his highly visual scheduling and monitoring diagram). Gantt Charts are drawn to display planned and actual project progress. A commonly accepted project management instrument these days. Gantt charts were subsequently used to monitor large construction projects like the Hoover Dam started in 1931 and Terminal 5 at Heathrow in London.

Critical Path

The shortest route through a series of interrelated tasks. Should a task on the critical path slip then the end date of the project would be jeopardized.

Most projects contain a large number of tasks. The critical path is the order of tasks that must be finished for the project to be considered complete. This path dictates the final finish date of your project plan.

The critical path is not primarily a list of vital tasks. It is a specific sequence of tasks, each task depending on the last. As the project progresses, different sequences might be named as critical.

What is a Critical Task

The definition of a critical task is any task that with a change of duration may positively or negatively affect the end date of the project if delayed.

Tracking the Critical Path

The Gantt chart and network diagram are two classic views in MS Project that will display the critical tasks and links in red automatically to make these tasks easier to observe and report.

Slack Time

Total slack is the amount of time that lies off the critical path. In other words changes to the duration of these tasks may or may not affect the critical path.

Slack is the amount of time a task can be delayed and still be on schedule. A 5 day task with a 10 day deadline has 5 days of slack. A task with no slack is automatically critical.

Task Constraints

There are two main types of constraint in a project called soft constraints and hard constraints. An example of a soft constraint would be when moving an office from A to B disconnect the computers as late as possible so people can still send and receive emails. No specific date in mind. As an example of a hard constraint imagine that when the office has moved the computers need setting up and you need to book in a network engineer. This would be an example of a hard constraint as the work must be executed on that booked day.

Splitting Large Tasks

Sometimes a task name might be too general to manage. You might have a task called “Plan the move” (duration 20 days). However, this could by split down into smaller tasks known as subtasks. For example, within the larger task “Plan the move” there might be smaller tasks to talk to a solicitor, draw up site layouts for prospective sites, check transport links etc.

Project Resources

These are the people, rooms, equipment, Materials that will be used or consumed by the project.

Resource Driven vs Fixed Duration

If it takes 1 day for a driver to get from London to Glasgow how long would it take two drivers? Of course the answer is the same maybe longer if they chat. However, if two people are packing files instead of one you would expect the task to be completed quickly, the first example is fixed duration and the second is resource driven.

John Caulfield
IT Trainer

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