PM 585 Week 4 Developing and Communicating the Schedule Example

Sixty Blocks, Nine Crews and a Paving Season: Developing and Communicating the Schedule for a Lead Line Replacement Project

[Student Name]

University of Phoenix

PM/585: Project Scheduling and Value Management

Week 4 Assignment

[Instructor Name]

[Date]

The water authority, its schedule, crews and dates are composites written for a model paper.

Allegheny Ridge Water Authority, the composite utility followed in PM 585, has scoped its first lead line program, broken it into 60 construction blocks and estimated about 2,230 crew-days of work with nine crews at peak. This paper turns those pieces into a schedule and plans how different people will see it.

Scheduling One Block

Each block follows the same sequence. Activities, typical durations and predecessors:

A. Mail notices to residents: 1 day; starts the block.

B. File the state one-call utility locate request and wait for marks: 3 business days; after A.

C. Obtain the street opening permit: 10 business days; starts with A.

D. Confirm access agreements and schedule visits: 5 days; after A.

E. Excavate and install replacements, about 40 lines: about 42 crew-days for one crew; after B, C and D.

F. Inspect each replacement: within one day of each installation; runs alongside E.

G. Temporary trench patching: alongside E.

H. Final pavement and sidewalk restoration by the paving contractor: 6 days; after E is complete and patches have settled for 14 days.

I. Block closeout, records and resident letters: 2 days; after H.

The longest path runs through C, E, the settling period, H and I: 10 + 42 + 14 + 6 + 2, or about 74 working days from first notice to closeout for one block. Permits, not locates or access, set the start of installation, so permit applications are filed three weeks ahead of each block.

Why Line of Balance

Repeating the block network 60 times in a conventional Gantt chart would produce hundreds of bars that hide the real question: are installation crews and the paving contractor moving through blocks at compatible rates? Arditi et al. (2002) reviewed line-of-balance scheduling for repetitive construction and noted that it shows production rates directly and helps keep crews working continuously, while also pointing out practical challenges such as handling different rates and non-typical units. Line of balance plots blocks on one axis and time on the other, with each activity drawn as a line whose slope is its production rate.

The Line-of-Balance Plan

Installation crews each complete one block about every 8.5 weeks. With eight crews starting in April and a ninth added in July, the installation line advances about 4.1 blocks a month in spring and about 4.6 in summer. The paving contractor, with two paving crews, can restore about 6.5 blocks a month. Because paving is faster, its line would catch up with installation and then stall; the plan therefore starts paving in June, after enough blocks have settled, and schedules it in two concentrated campaigns, June to July and September to early November, so the contractor works continuously. The plot shows that 30 blocks are installed in the first season and about 28 restored before the November deadline; the last two are patched and restored in April.

A crew waiting for the crew ahead of it is a cost; a crew running into the crew ahead of it is a hazard.

Resource Calendars and Weather

The schedule uses resource calendars rather than a simple five-day week. Installation crews work Monday to Friday, with Saturdays available for catch-up at overtime rates. The paving contractor works only when air temperature is above about 40 degrees Fahrenheit and pavement is dry, which in western Pennsylvania makes early April and late November unreliable. Asphalt plants in the region typically close for the season in late November, so the paving calendar ends there regardless of the contractor's availability. Building these calendars into the schedule moved the realistic end of the first-season paving campaign two weeks earlier than a plain calendar suggested.

Dependencies Outside the Project

Several dependencies sit outside the authority's control. The city streets department plans its own repaving program, and where a street is scheduled for repaving the authority moves that block earlier so that new pavement is not cut. A gas utility is replacing mains in two neighborhoods; those blocks are sequenced to follow the gas work. The schedule records these external dependencies as milestones owned by other agencies, reviewed monthly with them.

Leveling Inspectors

The authority has three inspectors. With nine crews each installing about one line a day, inspectors face about nine inspections a day across scattered sites, plus paving inspections. The first plan bunched all eight block starts into the first week of April, creating a peak of 16 inspection events on some days as crews finished their first, slow lines together. Staggering block starts by two or three days per crew reduced the peak to about 9, within the three inspectors' capacity at roughly three each a day.

Buffers and Uncertainty

Herroelen and Leus (2005) surveyed approaches to scheduling under uncertainty and distinguished reactive approaches, which repair a schedule after disruptions, from proactive approaches that build robustness in advance, including buffers. The authority uses both. Proactively, each crew's sequence carries a two-week buffer before the end of September, and the paving campaign carries a three-week buffer before the asphalt plants close in late November. Reactively, two ready-to-start blocks with permits and access agreements in hand are held in reserve so that a crew blocked by access refusals can move rather than wait.

Milestones

Key milestones: first-season construction start, April 7; ninth crew mobilized, July 7; 1,200 replacements complete, October 31; first-season paving complete, November 21; second-season start, April 6; all 2,400 replacements complete, October 30 of the second year; final paving, November 20; project closeout, January 31.

Four Views for Four Audiences

Board of directors: a one-page milestone chart and a line-of-balance summary showing blocks installed and restored against plan, updated monthly.

Crews and inspectors: a two-week look-ahead listing each crew's addresses by day, updated every Friday, with blocked addresses flagged.

Residents: a block calendar on the authority's website and door hangers 14 days and 2 days before work at each address, showing the expected day, the hours water will be off and a hotline number.

Funding authority: a monthly summary of replacements completed, spending and milestone status in the required format.

The current standard notes that schedule information should be presented in forms suited to each audience's needs and that visual tools can improve understanding (Project Management Institute [PMI], 2021).

Keeping the Schedule Current

The scheduler updates actual progress every Friday from inspector records, redraws the line-of-balance plot and flags any crew whose line falls more than two weeks behind. Changes that move a milestone go through change control from Week 1.

Conclusion

Scheduling the lead line program meant first understanding one block's network, where permits and the settling period drive the critical path, and then using line-of-balance planning to keep nine installation crews and a paving contractor flowing through 60 blocks. Leveling inspectors, buffering the paving deadline, holding ready-to-start blocks and tailoring four schedule views to four audiences turn the schedule into a working tool.

References

Arditi, D., Tokdemir, O. B., & Suh, K. (2002). Challenges in line-of-balance scheduling. Journal of Construction Engineering and Management, 128(6), 545-556. https://doi.org/10.1061/(ASCE)0733-9364(2002)128:6(545)

Herroelen, W., & Leus, R. (2005). Project scheduling under uncertainty: Survey and research potentials. European Journal of Operational Research, 165(2), 289-306. https://doi.org/10.1016/j.ejor.2004.04.002

Project Management Institute. (2021). A guide to the project management body of knowledge (PMBOK guide) (7th ed.). Project Management Institute.