SCHEDULING

Rohit ParkareMBARoll No. 13055.

What is scheduling

1. Assigning an appropriate no of workers to the jobs during each day of work.

2. Determining when an activity should start and end, depend on its

• Duration.• Predecessor activity (or activities ).• Predecessor relationship.• Resource availability.• Target completion date of the project.

In Production scheduling

Companies use forward and Backward scheduling .

• Forward Scheduling.

• Backward Scheduling.

Objectives of Scheduling

THROUGHPUT . TURNAROUND . RESPONSE TIME. OTHER RESOURCE USE. FAIRNESS. CONSISTENCY.

Other Scheduling objectives:

Fairness to all processes Be predictable Minimise overhead Balance available resources Enforcement of priorities Achieve balance between response and

utilisation Maximise throughput Avoid indefinite postponement and starvation Favour processes exhibiting desirable behaviour Degrade gracefully under heavy load.

There are three main Scheduling used:

Long-term Scheduling -The long-term scheduling controls the degree of multiprogramming and decides on which job or jobs to accept and turn into processes.

Medium-term scheduling-which determines which processes suspended and resumed?”

Short-term Scheduling:  Short term scheduling  is concerned with the allocation of processor  time to processes in order to meet some pre-defined system performance objectives.

Scheduling Levels : High level Scheduler (External priority)

is responsible for deciding which job currently on disc are to be brought into memory.

Low Level Scheduler (Internal Priority) is responsible for deciding which of the ready processes is to be run.

B E S T Scheduling

B E S T (Brihanmumbai Electric Supply and Transport)

BEST bus started in the year 1907. Total 4680 busses. 365 routes. 25 depots (region wise). 22000 bus drivers and conductors. It is considered a second heart of the

city.

BEST(Bus) SCHEDULING

1. Placement of the Bus Route. A. Route In New Area . 1. proper route placement- The route creation process .

2. Identify an area that needs new transit service Determine the terminus locations

3. Other factors Designing the route include the presence of other routes nearby

and the type of street the bus will travel upon. Except in very dense areas, parallel bus routes should be no closer than 1/2 mile to each other.

Speed bumps, speed humps, or traffic circles should also be avoided.

B. Route In Existing Area. Plan new bus routes operating in

areas with existing coverage. These new routes are often have

limited stop or express versions of existing local routes.

Provide direct service between two trip generator.

Service levels increase.

c. Placement of Bus Stops Appropriate distance between each bus stop. Placement of bus stops -the presence of trip

generators, transfer opportunities with other routes, and pedestrian access.

Adopting guidelines which allow for wider stop spacing offers several advantages to the transit system.

Site visit to determine the actual placement at the intersection.

Bus stops should be located at traffic signals, or at least marked crosswalks

D.Determination of Times for the Bus

Each route will at the very least have two timing points: the start and end of the route.

Optimum number of time points be selected for the route. For that

1. Estimate running time.2. Calculate the overall cycle time can

be determined.(Before and After )

E. Writing the Bus Schedule What our stops are. How long it will take to travel

between our stops 1. Using computer scheduling

software . The most important benefit of

scheduling software lies in its run cutting function.

2. For scheduling a particular route two things are important.

The service span of the route .For existing route – we would consider a

demand based service span based on the first and last trip.

If no body was riding-reduce the service span.

If a significant no. of people were riding-50 % or more-consider the service span.

3. Policy based service span and the run cutting process.

4. Policy based service span- specific time periods.

5. The run cutting process- make it easier and more cost effective to schedule the drivers

The frequency/headway of the route.

1. Demand based headway. How often buses will pass by a particular

point along the route. Minimum number of buses required per

hour. Load factor- maximum number of

passengers per bus, every seat is full no body is standing-i.e. in the ratio of 1.0 .

2. Policy based headway. Operate a minimal level of service. All of their routes operate at least

every thirty minutes whenever the subway is in operation.

From 4.30 AM to 2 AM Monday through Saturday

From 6 AM to 2 AM on Sunday.

Once the determination of service span and the headway the actual creation of the schedule is quite straightforward.

By using scheduling software .1. ESRI.2. Hastus.

F. Blocking, Run Cutting and Rostering.

Cutting the schedule. Blocking the trips. If the block operates out of closest

depot-saves deadline time and money.

Run cutting. Rostering.

THANK YOU