In any business, time is money—and managing it effectively can mean the difference between a project’s success and costly delays. Network Analysis provides managers with tools to plan, schedule, and control complex projects, while Queuing Theory helps businesses manage waiting lines, service capacity, and customer flow. Together, they ensure that operations remain both timely and efficient.
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Network Analysis – PERT and CPM for Project Management
Large projects often involve multiple activities that must be completed in a specific sequence. Network Analysis uses visual diagrams to map these activities, showing dependencies and timelines so that managers can allocate resources effectively. Two major techniques dominate this field: PERT (Program Evaluation and Review Technique) and CPM (Critical Path Method).
PERT is particularly useful when activity times are uncertain. It estimates the completion time using three values:
Optimistic time (O) – the shortest possible completion time
Most likely time (M) – the best estimate under normal conditions
Pessimistic time (P) – the longest expected duration
By applying a weighted average formula, PERT accounts for uncertainty and helps managers set realistic deadlines.
CPM, on the other hand, assumes that activity durations are known and fixed. It focuses on identifying the critical path—the sequence of activities that determines the shortest possible project completion time. Any delay in the critical path directly delays the entire project, making it a top priority for monitoring.
Critical Path Analysis and Time–Cost Trade-offs
Once the critical path is identified, managers can explore time–cost trade-offs, also known as crashing. This involves allocating extra resources (such as more labor, faster machinery, or overtime) to shorten project duration, but at an additional cost. By comparing the extra cost against the benefits of finishing earlier (such as meeting a launch deadline or avoiding penalties), managers can make informed choices.
For example, in construction projects, reducing project time might allow the company to take on new contracts sooner, justifying the additional expenditure.
Queuing Theory – Managing Waiting Lines
While Network Analysis deals with scheduling projects, Queuing Theory focuses on managing systems where entities (customers, calls, data packets) arrive to receive a service. Waiting lines, if unmanaged, can lead to customer dissatisfaction, reduced productivity, and wasted resources.
The M/M/1 model is the simplest queuing model, representing:
M: Poisson distribution of arrivals (random but with a known average rate)
M: Exponential distribution of service times
1: A single server or service channel
In this system, customers arrive randomly, are served one at a time, and the service times vary. The model helps managers calculate key performance measures such as:
Average number of customers in the system
Average waiting time in the queue
Server utilization rate
Practical Applications
PERT/CPM: Used in construction, software development, event planning, and manufacturing to ensure projects finish on time.
Queuing Theory: Applied in banks, hospitals, call centers, supermarkets, and computer networks to optimize service speed and reduce congestion.
By integrating Network Analysis for planning and Queuing Theory for operational flow, businesses can coordinate resources, avoid bottlenecks, and deliver better customer experiences.
Conclusion – Efficiency from Start to Finish
From planning projects to managing queues, Unit 5 combines two powerful operational tools. PERT and CPM ensure that projects are completed efficiently, with an eye on both deadlines and costs, while Queuing Theory ensures that day-to-day operations run smoothly, keeping waiting times minimal.
Businesses that master these techniques not only deliver on promises but also optimize the customer experience, strengthening their competitive edge in fast-moving markets.