Multi project scheduling techniques

Multi project scheduling techniquesBHUSHAN KAKDEROLL NO 214214003

CPM and PERT have been widely used for planning and scheduling The major drawback of these twotechniques is the assumption of unlimited resource availability.

Critical path through the project network is based only on the time requirements of the activities regardless of the resource requirements of each activity

The problem becomes more and more complex when the resources are allocated andshared among multiple projects. Multipleproject scheduling problemThe problem becomes more and more complex when multiple projects are involved. A multiple project scheduling problem consists of two or more number of projects, and a project is defined as a collection of activities, which consume resources as resources are limited then we have to give prfernece to some activity and shift the other activitiesApproachThe most common approach to scheduling and allocating resources to multiple projects is to treat the several projects as if they were each elements of a single large projectAnother way of attacking the problem is to consider all projects as completely independent

Single project approach Multi-project approachThis is also known as consolidation model. the consolidation model for real life projects are reported to have experienced many problems. These problems arise because of the unrealistic assumptions madeThe multi-project approach more realistically assumes that the different projects are related only through the resources.Classification of A Scheduling ProblemRESOURCE LEVELING

"Resource leveling aims to minimize the period-by-period variations in resource loading by shifting tasks within their slack allowances

The purpose is to create a smoother distribution of resource usage

Resource loading is the process of calculating thetotal load from project tasks on each resource foreach time period of the projects durationScheduling effectivenessThree important parameters affected by project scheduling are:Schedule slippageResource utilizationIn-process inventoryProject manager must select the criterion most appropriate for its situationSchedule slippage, often considered the most important of the criteria, is the time past a projects due date or delivery date when the project is completedResource utilization is of particular concern to industrial firms because of the high cost of making resources available. A resource allocation system that smooth's out the peaks and valleys of resource usage is ideal, but it is extremely difficult to attain while maintaining scheduled performance The amount of in-process inventory concerns the amount of work waiting to be processed because there is a shortage of some resource

Constrained Resource SchedulingHeuristicsHeuristics apply rules of thumb to determine which activities receive constrained resources first. Optimization modelsOptimization attempts to calculate the best solution using mathematical models. Two approaches to constrained resource scheduling heuristics and optimization models:Heuristic TechniquesThey represent rather simple extensions of well-known approaches to job-shop scheduling:

Resource Scheduling MethodMinimum late finish timeGreatest resource demand Greatest resource utilizationMinimum slackFirst come first served

Greatest Resource Utilization This rule gives priority to that combination of activitiesthat results in maximum resource utilization (or minimum idle resources) during each schedulingperiod.

Minimum SlackThis rule gives priority to that activitiesHaving smaller slack time

Mathematical ProgrammingThe three most common objectives of mathematical programming are:1. Minimum total throughput time (time in the shop) for all projects2. Minimum total completion time for all projects3. Minimum total lateness or lateness penalty for all projectsThese objectives are most appropriate for job shop type solutions to resource constraints

case studyA case study from an engineering industry is given below. The manger has to schedule five projects concurrentlynamely P1, P2, P3, P4, & P5 with 10, 12, 11, 6, & 10 activities as shown in Table1Table 2, 3, 4, 5, and6 gives the details about the activities, duration and resource required for performing each activity of all projects.The total number of resources available in the organizations 10 for each day. With these data the manager has to schedule the problem in an effective way and with less effortAssumptionThe Activity-on-Node (A-O-N) network is known for all the projectsThe activity duration and precedence relationships are deterministicActivity splitting is not allowedAn initial feasible schedule is determined by using the traditional critical pathCalculationSet current time t =1 and resources available at time t (Rt) = total resourcesavailable (Ra).

Conclusion and Result for case study

a genetic algorithm with a heuristic approach has been proposed to solve the multi project-scheduling problem with resource constraints and

To solve single project scheduling with resource constraint we have some Priority rules1 MINIMUM SLACK2 SMALLEST DURATION

SoftwaresWIN-QSBMS PROJECT 2013EXCEL TEMPLETS CONCLUSIONAs the No of project increases and no of constraint increases project scheduling become more and more complex for small and simple network we can use mathematical model but for large network we have to go for Heuristics REFERENCESProject management a systems approach to planning, scheduling, and controlling ha r o l d k e r z n e r , p h . dproject management a managerial approach jack r. MeredithSimulation model for resource constrained scheduling of multiple projects b. kanagasabapathi and k. AnanthanarayananProject management: the managerial process Erik w. Larson

Multi-project scheduling using an heuristic and a genetic algorithm Springer-Verlag London Limited 2006Thank You