Scheduling & Resource Planning CTC-415

Schedule Compression Used to decrease schedule time –At what price? Does cost of compression outweigh liquidated damages or possible profit from next job started early –What are costs? – extra crew, equipment –Benefits – less equipment time on job –How do you reduce time? Increase daily output on activity –Increases costs –Labor & Equipment

How to Compress a Schedule Look at critical path and determine activities which cost the least per day Look for logic revisions which could shorten schedule –Make sure that revisions don’t cause increased costs Painting and flooring can be done concurrently but at a loss of productivity –Keep activity relationships in mind

How to Compress a Schedule Activity Duration Reduction –Activities have a minimum duration IF 2 painters can paint a room in 2 days – how long does it take 4 painters?, 8 painters, 16 painters Setup times and cleanup times are always present –Results in increased costs –Must watch CP to make sure it does not shift

Linear relation – only true to a point Linear with break points Step function shows equip needs Parabolic costs increase as duration decreases Cost vs duration

Indirect costs change with project length –Shortened project reduces indirect costs –Lengthening projects increase in direct costs

How to compress schedule –1. Determine CP –2. Look for cheapest activity on CP and reduce 1 day – check CP (any movement) –3. Go to 2 –4. If multiple CP then must cut activities on all CPs –5. Total cost and days reduced

Example cut 6 days ActivityDaysCost/dayActivityDaysCost/day A2$1200H3$800 B1$600I3$2000 C1$800J4$1500 D3$1000K1 E1$900L2 F4$500M1$700 G2 N1$600

Scheduling Decompression May be able to increase duration of activity and decrease cost –Why? Keep crew busy ahead of schedule and payment slow down to keep handle on $ –How? Look at increasing duration by reducing crew