Understanding the Fundamentals of Integrated Master Schedules (IMS)
As a new project manager, have you ever been tasked with developing or reviewing an Integrated Master Schedule (IMS) and found yourself overwhelmed and unsure of where to begin? Or perhaps you have sat in meetings where IMS terminology felt unfamiliar or confusing? This article aims to guide new project managers through the fundamentals of IMS, breaking down its core components in a clear and approachable manner.
What is an Integrated Master Schedule?
An IMS is a comprehensive, time-phased plan that integrates all project tasks, milestones, and dependencies into a unified framework to guide project execution. Often used in large and complex projects, an IMS serves as a central planning tool to ensure alignment among all stakeholders and project teams.
However, the IMS is more than just a timeline; it is a dynamic tool that reflects the project scope, schedule, and resource allocation in detail. By providing a consolidated view of all project activities, the IMS helps project managers and teams to identify potential risks, allocate resources efficiently, and meet critical milestones.
Difference Between Project Schedule and IMS?
While a simple project schedule outlines tasks, timelines, and dependencies for smaller initiatives, an IMS goes further by integrating these elements into a comprehensive framework that incorporates resource allocation, milestones, and risk management. Both tools serve as guides for project execution, but an IMS is tailored for larger, more complex projects, providing a dynamic, centralized view for coordination across multiple projects. In contrast, a simple project schedule often suffices for smaller efforts, as it requires less maintenance and complexity.
In essence:
A project schedule is useful for managing individual projects and tasks within a specific, defined scope. For example: A schedule for a software development project, a marketing campaign, or a home renovation project.
An IMS is appropriate for managing a broader program or initiative that incorporates multiple projects and their interdependencies. For example, a large construction project involving multiple contractors; a program involving development of a suite of software applications; or design of a new car model requiring marketing, sales, and compliance.
What Makes an IMS Useful for Project Management?
Every tool, every process, every artifact in a project should serve a purpose that helps the project management team. There is no value in creating performative deliverables or proverbial checkboxes simply for the sake of appearances. Drawing inspiration from other successful projects is valuable, but adopting tools or methods beyond what is required can lead to inefficiency. For instance, does a three-month project truly necessitate a comprehensive Earned Value Management System? Likely not. Implementing more than what is absolutely essential wastes resources and complicates program management unnecessarily. In many cases, a simple project schedule meets the need perfectly without overburdening the process.
Organizations and project managers should assess the scope and size of the project to decide if an IMS or a simple project schedule is suitable. Additionally, it is important to customize and tailor the project schedule framework according to the specific scope and requirements of the project.
Key Components of an Integrated Master Schedule
An IMS typically includes these key components that ensure its effectiveness as a project management tool:
Work Breakdown Structure (WBS): The key to the IMS, the WBS divides the project into manageable work packages for scheduling and tracking. Each work package represents a specific deliverable or activity, ensuring thorough planning and execution.
Tasks and Activities: A comprehensive list of tasks and activities necessary to complete the project. Each task is precisely described with specific objectives, durations, and allocated resources. These tasks are typically sequenced and linked to demonstrate relationships.
Milestones: Significant events or deliverables that represent important stages in the project timeline. They provide an overview of progress and serve as key decision points for stakeholders.
Duration: Each task and milestone in the IMS are associated with specific start and end dates. These timeframes ensure that the project stays on track and provides a basis for measuring progress.
Task Relationships and Network Logic: Mapping of the relationships between tasks, showing how the completion or the start of one task impacts others. These dependencies can be categorized as Finish-to-Start, Start-to-Start, Finish-to-Finish, or Start-to-Finish.
Lags and Leads: Specified in the timeframe, a Lead is when a successor task can start before the predecessor task is complete, allowing it to begin earlier. On the other hand, a Lag is the delay put on a successor task, meaning it can only start after a certain period following the completion of the predecessor task.
Resource Allocation: Identified and allocated resources—both human and material—that are required for each task. Proper allocation ensures that resources are available when needed and helps to avoid bottlenecks.
Critical Path: The longest sequence of tasks that determine the project deadline. Identifying it helps understand the timeline and prioritize key activities.
Risk Management: The IMS often incorporates risk mitigation strategies for tasks that carry significant uncertainties. This allows project managers to anticipate challenges and develop contingency plans.
How to Create an IMS?
Developing an IMS requires careful planning and collaboration among stakeholders and project teams. Here is a step-by-step guide to creating an effective IMS:
Determine the Project Scope: Using the project scope and requirements documents, clearly articulate the project objectives, deliverables, and constraints. This will form the basis for all subsequent planning activities.
Develop the Work Breakdown Structure: Break the project and its activities into manageable components using a WBS. Each component should represent a distinct deliverable or task.
Identify Tasks and Milestones: Identify a list all tasks and milestones for the project, ensuring they are specific, measurable, attainable, realistic, and time-bound.
Identify Relationships: Determine the relationships and sequences between tasks to identify the dependencies. This will assist in organizing activities, creating the Network Logic, and understanding the critical path.
Allocate Resources: Distribute resources to each task, considering their availability, accessibility, and constraints. Include both human and non-human material in the resource allocation efforts. Ensure efficient allocation to prevent bottlenecks.
Set Durations: Determine the length of each task and specify start and end dates. Use these durations to develop a detailed project schedule.
Review and Validate: Engage and collaborate with stakeholders and project teams to assess the IMS for accuracy and completeness. Make necessary adjustments to ensure alignment with project objectives.
Baseline: An IMS must be continuously monitored and updated regularly to reflect changes in scope, resources, or timelines. Considerable changes to scope, resources, or timelines should result in creating a new baseline. This allows for basis comparisons during retrospectives. Continuous monitoring ensures the project remains on track.
What Spells Failure for an IMS?
More often than not, the IMS under scrutiny is missing critical ingredients. Failure starts with poor development and accelerates with neglect. The IMS needs to be robust and solid, and a baseline must be set before the project starts. However, IMSs frequently fail due to the same common mistakes.
The optimistic under estimator: “Afterall, how hard can a Gantt Chart be? I can whip one up and it will be good.” IMSs are not simple, they are dense and complex, consisting of multiple layers of information generated after thorough analysis of the requirements and scope for each project involved. Many people mistakenly believe that developing an IMS is easy, but this often results in failed efforts. First the schedule slips, followed by cost and quality. Then stakeholders start asking what happened, and it is already too late. “But we had an IMS!”
The not-so-integrated master schedule: Although referred to as an IMS, often IMSs are not integrated. They are typically stovepiped and ignore shared resource pools, competing interests, and perspective across the enterprise. There is no integration, manual or automatic, that feeds progress information or resource availability.
The complete but neglected IMS: Maintaining and updating the IMS is often deprioritized due to its time-intensive and costly nature. This leads projects to supplement the IMS with simpler scheduling tools, such as date trackers or task trackers, to forecast key dates. By this point the IMS fails to even be the locus for scheduling.
These mistakes leave us with an IMS that is; not integrated; certainly not master; and not the main scheduling tool. It’s a Disjointed Novice Timeline.
The key takeaway here is that the main scheduling tool and its upkeep demands have to be commensurate with the overall effort of the project. There has to be a logical and convenient way to update the progress of activities. These updates also must happen on a consistent drumbeat to provide actionable information to the project management team.
Best Practices for Managing IMS
When used effectively and constructively, an IMS yields significant benefits. Implementing following industry best practices can lead to substantial improvements in results.
IMS Basics:
A consistent method for periodically updating the activities in the IMS is required
At least one IMS Baseline must be saved prior to the start of the project
The project must have a start and end Milestone
Managing Discrete Work:
Discrete Work must be organized into a logical WBS, oftentimes aligned with the contractual WBS if it exists
Discrete Work must have Network Logic tied to a meaningful Milestone
Every Discrete Activity should have at least one logical predecessor and one logical successor
LOE activities must never drive the Critical Path
Time Management:
Activities with durations longer than a single update period should be limited
Long-duration activities should be decomposed into shorter activities
Activities must be scheduled Automatically–they must be rearranged logically by the scheduling platform when a calculation is performed
Relationships:
Maintain Network Logic at or near the lowest levels (Outline Level in MS Project)
The usage of Start-to-Start (SS), Start-to-Finish (SF), and Finish-to-Finish (FF) should be limited, with strict avoidance of Start-to-Finish relationships. They are the most difficult to manage and are rarely necessary. Use Finish-to-Start (FS) wherever possible.
Never assign Network Logic to a Summary Task
Relationships should begin with a Milestone to Discrete Tasks, concluding with a Milestone
Avoid hard constraints where possible, except for the project Start and Finish milestones
On Discrete Work vs. Level of Effort
It is crucial to differentiate between Discrete Work and Level of Effort (LOE) activities, especially in the context of scheduling. Discrete Work leads to a specific and measurable outcome, while LOE encompasses administrative and managerial tasks. For example, while tracking activities like Program Management or Supervision might be significant to the project, they should not influence Critical Path calculations. If these activities are included in the schedule, define a mechanism to ensure they do not drive the Critical Path.
For example, some project schedule platforms do not inherently allow for the exclusion of LOE activities from the Critical Path if progress has been logged against them. There are various workarounds to this, but the most effective one is to flag these activities and temporarily delete them during Critical Path Analysis.
On the Critical Path
Textbook definitions of the Critical Path are often a bit abstract. In simpler terms, the Critical Path is all the activities that will delay the completion of the project if they are delayed. For example, if I add one day of duration to User Acceptance Testing (UAT) and the Project Completion Milestone slides one day, then UAT is on the Critical Path. Once the project schedule is finalized and baselined, it is essential to identify and delineate the Critical Path. This will enable diligent monitoring and control over the critical path to mitigate potential delays.
On the Float and Schedule Margin
Total Float is typically calculated by the scheduling platform (e.g. Microsoft Project, Primavera) and it means how much time the completion of an activity can be delayed before it begins driving the Critical Path. It answers, “How late can this single activity be before it becomes an issue?” This process assists in recognizing and managing risks, and in taking advantage of opportunities.
It’s recommended that the schedule end with a Must-Finish-On Milestone, preceded by a free-floating internal Finish Milestone. The difference between the two serves as the Schedule Margin. With this logic established, it is all about managing Total Float on that internal Milestone.
Understand your Critical Path thoroughly and monitor activities on the Near Critical Path, which depends on the IMS's length and complexity. The threshold for Total Float on an activity that determines Near Criticality is somewhat arbitrary. If the schedule spans over several years and consists of thousands of activities, this threshold might be two weeks. For simpler or shorter projects, the Total Float might be a matter of days. Some important questions considered are: if a Near-Critical activity is delayed one month, what happens to your Schedule Margin? Did you blow through it? Can you add more resources to crash the schedule?
On Network Logic
An essential component of managing the IMS involves understanding and adjusting the rigidity of the Network Logic, which defines the relationship and flexibility of tasks based on various factors. In other words, is the sequence of activities unwavering to creative solutions, or can you rerack the sequence if conditions change? There are pros and cons to this approach. For example, does a Critical Activity requires weather to cooperate in order to perform it? If your schedule is late by one month, would it be too cold or too rainy to complete the weather dependent task?
Network Logic frequently includes preferred options and sequences. It is essential to understand potential pitfalls beforehand and develop mitigation plans so that this part of the Network Logic can be replaced or adjusted if a risk materializes. Managing the Network Logic is closely related to the process of risk and opportunity management, which enables teams to monitor risks and opportunities arising from possible scenarios. For example, if the preference is to use a mainstream retailer to purchase materials at a lower cost, but the retailer has a significantly long lead time, one way to mitigate the risk of schedule delays is to choose a small local business that offers a shorter lead time at a higher cost. Clearly it would not make sense to have both scenarios in the IMS, however this risk and the mitigation plan should be identified and maintained in the risk register.
On Resources
Similar to the rigidity of network logic, it is critical to know how flexible your resources are. An IMS can have its Critical Path influenced by the availability of resources, which includes both human capital and non-human material resources. For example, if the project requires a specific crane, the PM needs to know when it is actually available.
Depending on the project, there may be opportunities to assign activities to alternate distinct resource types, with the initial choice often driven by preference. This is where the resource-leveling features in scheduling software platforms prove invaluable—a topic worthy of deeper exploration in its own right.
Conclusion
An IMS, when developed and used effectively is the catalyst for successful Program Management. While the creation and maintenance of an IMS involves significant work, it is not daunting when relevant elements are included and carefully balanced. There are several critical factors that must be considered for the IMS to function effectively as a program management tool. While these fundamental factors are vital, they are frequently overlooked. Follow the guidance provided in this article to draft and maintain an IMS.
Keep in mind, the IMS is an evolving document that needs regular evaluation and continuous updates. Establishing a cadence for reviewing status, adjusting parameters, and periodically revising the schedule is essential. It is critical to ensure that the schedule remains robust and healthy by evaluating it using DCMA’s 14 Point Health Metrics or a similar analysis tool.
Finally, use the IMS! Given that considerable time and diligent effort were invested in its development, it is important to make use of it. Engagement in program management should never be superficial or performative, that time is an essential resource that can be allocated to enhancing other aspects of the project.
