Understanding Gantt Charts Chris Croft
Why are Gantt charts so important to customers?
1. Easily show schedule, budget, and scope 2. Easily show customer their deliverables, due dates, impact of delays 3. Shows that you're systematic, organized, experienced 4. Can demonstrate more options (trade offs between schedule, budget, scope, quality)
What are the 4 ways tasks can be linked?
1. Finish to start 2. Start to start 3. Finish to finish 4. Start to Finish
Where should you anticipate risk in your Gantt chart?
1. If you have multiple one-day tasks in a row...things never just take a day—there will be delays 2. If floating tasks are nearly critical 3. If your plan has lots of small tasks at the end
Why make two versions of a Gantt chart?
1. In the first, make a chart where floating tasks are dropped in the middle of their range. 2. Make a chart In which you place all floating tasks strategically
What are the four main uses of the Gantt chart?
1. Planning the project 2. Explaining the project to others 3. Monitoring the project 4. Adjusting the plan
How do you successfully insert floating tasks into a Gantt Chart?
1. Put in vertical lines marking critical task start and stop points 2. Sharing a float: floating tasks can share a time 3. Floating tasks can depend on other floating tasks 4. Decide whether to float tasks earlier or later
What are the 4 uses of Gantt of Gantts?
1. Say no to new work 2. Have customers establish their priorities 3. Replanting when additional work comes in 4. Monitoring progress
What are the customer's three interest points?
1. Scope: What I'm going to get 2. Budget: What it's going to cost 3. Schedule: When it will be done
What are common mistakes?
1. Skipping the network diagram 2. Having the wrong level of granularity 3. Forgetting contingency 4. Neglecting the Gantt chart once you've started 5. Changing your plan more than once. You get one shot halfway through
Visual evaluation of Gantt charts?
1. Too flat & linear: possibly too conservative 2. Too vertical: possibly too risky 3. Avoid paths that have lots of small, fast tasks at end
What to avoid in tasks on Gantt charts?
1. Too many tasks (more than 30). 2. One task that is longer than the others 3. A furry of small tasks at the end 4. A good mix of series and parallel
What debate is currently going on in project management?
A debate between traditional Gantt chart management and Agile
What is a Gantt of Gantt?
A master plan of all projects being conducted at one time
What is Agile?
A methodology for dealing with a lot of unpredictability
What is the APM/PMI method?
A planning method known as traditional or Waterfall
How do you manage excessive granularity? Say you have more than thirty tasks?
A sub-Gantt. Have a nice, clear overview plan with the smaller details tracked in a sub-Gantt
How are Gantt charts related to resource allocation?
By adding columns and rows you can see the relative resources consumed by particular tasks as well as particularly intense periods of the project. You can address these by rethinking the elements of true project (schedule, budget, scope).
What do you have to do before drawing your Gantt Chart?
Draw the Network Diagram
What are the arguments for floating tasks early or late?
Early: you won't be in as much trouble if you hit delays Late: you'll save money if tasks are hiring others or buying supplies
What do nodes show in PERT?
Events
Why have a Gantt Chart at the second kick off meeting?
Everyone can see their roles and can commit to those roles
Which is the best way to link tasks?
Finish to start
What is the FCC?
Forecast Cost at Completion
How much contingency should you build in?
Half way between average and worst case will give you 90% certainty of success
What units of measure for resource plan?
Hours/week, Person per days/week OR month, Number of people (FTEs)/week OR month
How to assess risk?
How likely X How serious (each valued 1-5); mitigate any double digit risk
What is the simplest way to manage time lags?
Identify lags as a task (Waiting)
What complications can arise in a Gantt Chart?
If you have two simultaneous critical paths...just stack them
When was PERT developed?
In 1957 to help the US Navy support the Polaris Nuclear Submarine project
How do you speed up your project?
Increase money, decrease quality, overlap tasks
Why is granulating helpful?
It allows you to insist on a clear gate pattern. IE, if you don't want to hire staff until the manager is hired, but sense there could be overlap, then divide the task of hiring staff into first round and second round interviews and only conduct first round interviews while completing the manager's hiring process. Then, do second round interviews with the manager in place.
What are the weaknesses of Agile?
It doesn't deliver, from the beginning, on the customer's three interest points
What is PERT?
Program Evaluation and Review Technique
What are the two methods for coloring tasks?
Proportional coloring (color in what you've done as you go) OR Color when complete (do t color in any part of task until entire task is completed)
What are strengths and weaknesses?
Proportional coloring: tells you more but open to self delusion; Color when complete: always accurate but only when it tells you something
What are the relative strengths and weaknesses of MSProject?
Pros: MSProject makes it easy and fast to draw Gantt charts; also makes it easy to see what if's; it looks impressive. Cons: MSProject is expensive and you have to learn it. Also, it has a mind of its own and you have to fight it. It encourages bad habits such as not drawing the Network diagram first. Keep it simple
What are relative strengths and weaknesses of Excel?
Pros: You can share it easily; You can add up costs and times easily; you can use it for resource planning for multiple projects; Everyone has it and knows it
What is the first step in drawing a Gantt chart?
Put in the critical path
What is granularity?
The degree to which tasks are broken down
What is another name for the resource plan?
The loading plan (even the load by moving floating tasks so you don't have really tough weeks when avoidable).
What is the Critical Path?
The longest path
What are the three levels of resource planning?
The network diagram, the Gantt chart, the Gantt of Gantts
What is Chris's rule?
You can only reschedule once. Do it half-way through.
What happens in the first kick off meeting?
You discuss the project
What is an FTE?
full time equivalent
How do you generate a predicting spend curve?
Use the Gantt chart to look at spend compared to schedule.
How often should you color in what you've done?
Weekly or monthly
When do you add in contingency?
When you convert the network diagram to the Gantt chart
Top tips for creating Gantt charts easily in Excel
1. Use conditional formatting to color in the squares 2. Use weeks as time measurements and highlight all columns and pull them In So that you can see entire Gantt chart on one screen 3. Insert dates using the full series strategy by typing in first two dates only 4. Turn the dates onto the diagonal to fit them into the columns Format>Format Cell>Alignment 5. Add up time spent vertically and horizontally in a sum column (vertical) and inserted table 6. Copy chart onto a second sheet to keep track of costs instead of time 7. If you have a task that is just waiting time (no hours or dollars spent), then enter the letter O instead of he number zero and the cells will still be colored in, but not counted in totals 8. Insert blank columns for holidays after map is done to capture what will happen in real life 9. Use total numbers (hours, costs, people) to paste into master Gantt to understand how your whole life is working 10. Because of conditional formatting, you can't complete color the cells, so color a cell outside your chart area and then use the paintbrush
What are APM/PMI's four methods for coping with uncertainty?
1. Use the worst case 2. Use the most likely case 3. Add contingency to allow for unknowns 4: divide the project into phase 1 and phase 2
What software options exist for producing Gantt charts?
1. excel 2. MS Project 3. Cloud-based free software 4. Custom-tailored systems
How do you wisely manage resources?
1. identify bottlenecks 2. Identify can't move projects
How many ways to show time in PERT?
3-optimistic, expected, pessimistic
What do arrows show in PERT?
Activity
What is the forecast Completion Date
Actual time/expected time X plan
How do you include the contingency in your critical path?
Add a little but to each of the critical tasks. This hides it (if you lump it all in one place, your boss will pull it out) and allows you to acknowledge that you're not sure where it will happen.
How do you calculate contingency for a year long project that might go four months long?
Add an extra two months (half of the worst case): 16 month project
What is the term PERT used to describe now?
All critical path scheduling models (even CPM)
Who developed the Gantt chart?
American Henry Gantt in 1910
What is best?
Cloud based is too flaky; customized systems are usually too expensive and complicated. Use Excel or MSProject
How to solve the trade offs between Proportional coloring and Color when complete?
Color when complete with granularity
What is CPM?
Critical Path Method
What is the easiest but most underused capability of Gantt chart?
Monitoring progress
When you reschedule resources, how much do you ask for if you've already overrun?
More than enough.
Can you draw the Gantt Chart before you know the critical path?
No! That's why you draw a Network Diagram first (PERT, CPM, Post-it Picture, etc.)
Do Gantt charts have any rules on the vertical ordering of tasks?
No. But there are strategies for making the chart easier to read. On the critical path have the tasks that begin earliest stack highest. On floating tasks, follow the same strategy, but also "nest" tasks so you don't disrupt vertical lines
Is a list a project plan?
No. Only a Gantt chart is
Why is every task given its own line?
So that you can show slippage
What do you do with overlapping tasks?
Stack them or Granulate them (meaning cut them up into smaller tasks)
How do you calculate expected time in PERT? Where expected time is TE; most likely time is m; optimistic time is o: and pessimistic Time is p?
TE=(o+4m+p)/6
What is the FCC?
The Cost Performance Index X plan
What is the Cost Performance Index?
The actual spend/budgeted spend
What is the FCC in detail?
The actual spend/budgeted spend X plan
What is the important detail that must be affixed to each task in the network diagram?
The time it will take
What is usually the major factor in PERT projects?
Time
How is a Gantt chart organized?
Time on the horizontal axis; tasks on the vertical axis
What are time lags? (Lead and lag)
Time that needs to pass between finishing one task and starting another
