CE 331: Design Scheduling, Monitoring, and Progress Control

Comprehensive vocabulary flashcards covering Activity-On-Node scheduling, Critical Path Method calculations, design phases, work progress measurement methods, and Earned Value Analysis.

Activity-On-Node (AON) Network

A directional flow chart used to organize a project schedule where each activity is represented by a node carrying the duration, and arrows represent dependencies without carrying durations or labels.

Milestone (AON)

A dummy node in an Activity-on-Node network, represented as a diamond, which has zero duration and marks the beginning or ending of a significant event rather than an activity.

Critical Path

The path of longest duration through an activity network, consisting of the series of activities that directly control the overall project duration and will delay the entire project if delayed.

Float

The amount of time non-critical activities can shift or be delayed without extending the total project duration, calculated as $\text{LS} - \text{ES}$ or $\text{LF} - \text{EF}$.

Finish-to-Start (F-S)

The most common precedence relationship between activities, where a successor activity cannot start until the predecessor activity has finished.

Start-to-Start (S-S)

A dependency relationship where the successor activity cannot start until the predecessor activity has started, allowing activities to run in parallel.

Finish-to-Finish (F-F)

A precedence relationship requiring that a successor activity cannot conclude until the predecessor activity has finished.

Best Practice for Lag and Lead

The practice of converting lag or lead time into an intermediate activity (such as curing concrete) to clarify work sequence and reduce scheduling errors or confusion.

Early Start (ES)

The earliest date an activity can begin based on network logic, calculated during the forward pass as the maximum of all immediate predecessors' Early Finish dates: $\text{ES} = \max(\text{Predecessor's EF})$.

Early Finish (EF)

The earliest date an activity can finish, calculated during the forward pass by adding the activity duration to its Early Start: $\text{EF} = \text{ES} + \text{Duration}$.

Late Finish (LF)

The latest date an activity can finish without delaying project completion, calculated during the backward pass as the minimum of all immediate successors' Late Start dates: $\text{LF} = \min(\text{Successor's LS})$.

Late Start (LS)

The latest date an activity can start without delaying project completion, calculated during the backward pass as $\text{LS} = \text{LF} - \text{Duration}$.

Forward Pass

The critical path method step that moves left to right through the network to calculate the Early Start ($\text{ES}$) and Early Finish ($\text{EF}$) for each activity and determine total project length.

Backward Pass

The critical path method step that moves right to left from project completion to determine the Late Finish ($\text{LF}$) and Late Start ($\text{LS}$) of each activity without extending total project duration.

Schematic Design (SD) Stage

The initial design stage focused on establishing the overall design concept primarily for the owner, representing approximately $30\%$ design completion.

Design Development (DD) Stage

The intermediate design stage where the design is developed in greater detail considering constructability and cost primarily for design team members, representing approximately $60\%$ design completion.

Construction Document (CD) Stage

The final design stage where the design is detailed to the 'nut-and-bolt' level and construction drawings/specifications are prepared for the construction team, representing approximately $90\text{--}100\%$ completion.

Start/Finish Method

A progress measurement method assigning an arbitrary percentage ($0\%$ for short tasks, $20\text{--}30\%$ for longer tasks) at the start and $100\%$ at completion; used when tasks lack well-defined milestones or have hard-to-estimate durations (e.g., aligning equipment, design studies).

Units Completed Method

A progress measurement method calculated as $\frac{\text{parts complete}}{\text{total}}$; used for repetitive tasks requiring uniform effort (e.g., writing specifications, installing wire).

Incremental Milestone Method

A progress measurement method calculated as the sum of sequential milestones completed based on assigned work-hours; used for tasks with distinct, chronological milestones of uneven effort (e.g., production drawings, procurement, installing major equipment).

Ratio Method

A progress measurement method calculated as $\frac{\text{Actual cost or work-hours to date}}{\text{Forecast at completion}}$; used for ongoing administrative/support tasks lacking a specific end product and budgeted on bulk allocation (e.g., project management, quality assurance).

Earned Value Analysis (EVA)

A project controlling method that combines the Iron Triangle (work, cost, time) into a unified graph to identify project deviations from planned schedule and budget in order to take timely corrective action.

Budgeted Cost of Work Scheduled (BCWS)

The planned expenditure representing how much money was originally budgeted to be spent by a specific point in time.

Actual Cost of Work Performed (ACWP)

The actual expenditure incurred to date representing how much money has been spent by a specific point in time.

Budgeted Cost of Work Performed (BCWP)

The earned value representing how much budgeted money was earned from the work actually completed by a specific point in time.

Cost Variance (CV)

A metric indicating cost performance calculated as $\text{CV} = \text{BCWP} - \text{ACWP}$; a positive value indicates the project is under budget, while a negative value indicates over budget.

Schedule Variance (SV)

A metric indicating schedule performance calculated as $\text{SV} = \text{BCWP} - \text{BCWS}$; a positive value indicates the project is ahead of schedule, while a negative value indicates behind schedule.

Work Package Overlap

A project breakdown error where two or more work packages encompass the same scope or component (e.g., both listing controls installation), creating ambiguous boundaries and unclear contractor responsibilities.