Linear scheduling LSM
- 1. Linear Scheduling Method LSM Definition A simple diagram to show location and time at which a certain crew will be working on a given operation. 1
- 2. Characteristics Shows repetitive nature of the construction. Progression of work can be seen easily. Sequence of different work activities can be easily understood . Have fairly high level of detail. Can be developed and prepared in a shorter time period than other formats. 2
- 3. LSM Schedule s 4 nd e F Slab 3 v at nds & ca PF Ex F& e 2 Fram 1 2 4 6 8 10 12 14 16 18 20 22 24 3
- 4. Advantages of LSM In certain types of projects: Provides more information than a bar chart. Offers advantages over network diagram. 4
- 5. Line of Balance Technique LSM has relationships to the line of balance (LOB) technique, developed by US. Navy in the early 1950s. First applied to industrial manufacturing and production control. 5
- 6. Three diagrams are used in LOB: 1. Production Diagram Shows the relationships of the assembly operations for a single unit. Similar to AOA, except that it shows only one unit of production. 2. Objective Diagram Used to plot the planned or actual number of units produced vs. time. LSM diagram resembles this diagram. 3. Progress Diagram Shows the number of units for which each of the sub-assembly operations has been completed. 6
- 7. Difference between Objective Diagram and LSM : Objective Diagram is used to schedule or record the cumulative events of unit completion. LSM is used to plan or record progress on multiple activities that are moving continuously in sequence along the length of a single project. 7
- 8. Implementation of LSM Can be used to continuous activities rather than discrete activities. Linear: Transportation projects; highway const., highway resurfacing and maintenance, airport runway const. and resurfacing, tunnels, mass transit systems, pipelines, railroads. High-rise building construction Repetitive building units 8
- 9. Elements of the LSM Axis Parameters Location Measure of progress. In high-rises and housing const., measures may be stories, floors, subdivisions, apartments, housing units In Transportation projects, distance (ft. or mile can be used, but division by stations (100ft.) is common) is general. 9
- 10. Time Hours, days, week, or month - depends on the total project time and level of detail desired in the schedule. Preferable to prepare the schedule based on working days and convert to calendar days only at the end. 10
- 11. Activity Production Rates Obtained by the usual estimating methods as a function of the activity, equip. characteristics, labor, and job conditions. The initial rate should be associated with the min. direct cost of accomplishing the single activity. 11
- 12. Activity Interruption and Restraint Prod. rate may vary with locations or time periods. Progress may be interrupted intentionally and restraints may occur between activities due to limited equip. or crews. 12
- 13. Buffers When const. activities progress continuously in a chain, some spacing between activities is required. This spacing serves as a buffer and may be required distance or time interval between activities. 13
- 14. Activity Intervals Used to describe the period of time between the start and finish of an activity at a particular location. Intervals can be indicated by broad line, two narrow lines, etc. Monitoring Progress Working or calendar can be marked with a moving symbol or a line, tape, etc. vertically across the diagram. Progress on individual activities would be marked by location rather than time. 14
- 15. 1. Project Time Optimization The total project time may be such that indirect costs and liquidated damages assessed are more costly than the expense of accelerating certain activities. Cost-duration analysis can be used to minimize the total cost, as follows : 15
- 16. a) Identify all activities that can be accelerated or decelerated. b) Among the above, consider only those that are at a buffer limitation at both the start and the finish of the activity. c) Of these, select the one activity with the lowest cost slope associated with acceleration (or deceleration). d) Accelerate (or deceleration) the activity rate of production the maximum feasible amount. e) Repeat the above steps successively until the optimum project cost and associated duration is obtained. 16
- 17. 2. Discrete Activities Discrete are best scheduled by other methods. Once the duration is determined by network analysis, it can be scheduled on the LSM diagram and coordinated with the linear activities. 3. Seasonal Adjustments When developing LSM, appropriate adjustments can be made for seasonal effect on construction progress. 17
- 18. 4. Project Progress and Resource Management Project progress is often estimated by the S-curve when bar chart development. In LSM, the determination of activity progress is facilitated and made more rigorous. 18
- 19. Four-unit Duplex I-J Fragnets 2 7 8 EXC FNDS F&P FNDS FRAME BLDG 1 & SLAB BLDG 1 BLDG 1 2 7 8 EXC FNDS F&P FNDS FRAME BLDG 2 & SLAB BLDG 2 BLDG 2 2 7 8 EXC FNDS F&P FNDS FRAME BLDG 3 & SLAB BLDG 3 BLDG 3 2 7 EXC FNDS F&P FNDS BLDG 4 & SLAB BLDG 4 19
- 20. Bar-chart vs Linear Scheduling 20
- 21. 5000 4000 Time Buffer 3000 Space Buffer 2000 1000 5 10 15 20 25 30 35 Space buffer = how many meters separated (pick a day) Time buffer = how many days separated (pick a location) 21
- 22. 5000 Client in town for 4 days 4000 3000 2000 1000 5 10 15 20 25 30 35 Curtain = Showing important event 22
- 23. LSM Schedule These lines are Duplex Number 4 actually different ns io 3 d at un 2 Fo t e 1 a va c Ex 2 4 6 8 10 12 14 16 18 Days 23
- 24. LSM Schedule Duplex Number 4 ns t io b 3 da & Sla n s 2 ou ation e F Fo und t 1 va a F&P Exc 2 4 6 8 10 12 14 16 18 Days 24
- 25. 2 NW FORM 17/7 2 NE REBAR 19/7 SETUP 25/7 FORM 19/7 REBAR 21/7 POUR 26/7 SETUP 27/7 POUR 28/7 2 SW 2 SE FORM 25/7 FORM 21/7 REBAR 27/7 REBAR 25/7 SETUP 1/8 SETUP 31/7 POUR 2/8 POUR 1/8 GRAPHIC PRODUCTION SCHEDULE – ELEVATED FLOOR SLAB 25
- 26. AHU COMPONENTS EXHAUST FAN RETURN FAN SUPPLY FAN AIR PIPING EQUIPMENT PLANNED PLANNED HANDLING LOCATION START FINISHED UNIT AHU 101 MER 1 8-Jun 7-Jul AHU 102 AHU 201 MER 3 6-Jun 4-Jul AHU 202 O I R C PRODUCTION SCHEDULING O ORDER – MATRIX SCHEDULE R RECEIVE I INSTALL C CHECK-OUT 26
- 27. AHEAD OF PLANNED TOTAL SCHEDULE EXCAVATION (CU.METER) 30000 AHEAD OF PLANNED PRODUCTION 25000 20000 15000 10000 5000 MAY PRODUCTION SCHEDULING – VELOCITY DIAGRAM 27