A project is just a set of activities that have to happen in the right order. A network diagram lays them out so you can see how long the whole thing takes, where there is spare time, and which activities cannot slip without delaying everything else.
This is No Slack Solutions, a consultancy that untangles project plans for a living. Three clients are waiting, each with a tighter plan than the last. Your task is to read each network, find what cannot slip, and steer the client away from a missed deadline.
You are the new intern at No Slack Solutions. Colin and Flo will hand you three live client briefs, one at a time, and let you make the calls. Get it right and the clients hit their dates. Get it wrong and someone pays for it.
"Same rules on every client. Before you touch a single brief, learn to read the diagram. It is quicker than it looks."
In plain terms: float is slack. Activities on the critical path have a float of zero. The bigger an activity's float, the more it can drift before anyone needs to worry.
"Every client's plan works the same way: activities in the arrows, events in the circles, and one chain that sets the finish date. Find that chain and you find where the pressure really is."
"I have walked away from a steady salary and put my savings into the lease. The landlord charges rent from day one whether the doors are open or not. I have booked the launch night for day 25: eighty guests, a local food writer, and a band. If we open late, I lose the launch buzz, I am refunding tickets, and I am paying rent on an empty room. I cannot afford that."
"Before we manage anything, read the plan. Tap the activities you think cannot slip, the ones with no spare time. That chain is the critical path. Take your best guess, then lock it in."
Tap to mark the activities you think have no spare time:
"A boutique hotel ordered sixty handmade chairs. Delivery is locked to day 28, with a penalty in the contract if I am late, and if I lose this order the hotel drops us for good. I have four makers. Lose this contract and two of them are out of work. Right now the fabric side is slow: preparing the upholstery (activity E) is running about four days over. Does that move my delivery?"
"This one is mine. Spare time. The fabric prep is over by four days. Either the plan soaks it up, or it pushes the whole delivery. Read the diagram, work out the float on activity E, and call it. Then we watch the model."
Tip: float on E = (LFT at E's finishing circle) minus (E's length) minus (EST at E's starting circle).
Halton is moving its whole operation to a new site during a four week shutdown. Everything must be live by day 31. They have hit a snag: fitting the new racking (activity B) has run into structural problems and now needs 13 days instead of 9. That pushes go-live to day 35. Miss the window and they cannot fulfil the Christmas contracts: hundreds of orders, and the client has warned they will walk.
"I have budget for one extra crew, no more. Put them on one activity and they will take about four days off it (an activity cannot drop below one day). Where do I send them so we are live by day 31? Get this wrong and I am explaining to the board why we lost the contract."
"One question, intern: is the activity on the critical path? Spend that crew anywhere else and you have spent it on nothing."
"I have marked the spare time on each card. Read it before you commit the crew."
Send the extra crew to one activity. Each card shows how much spare time that activity has right now:
When a project slips, a good manager does not panic about every late activity. They ask three things, in order:
This is the heart of network analysis: not every delay matters equally, and the diagram tells you which ones do.