Scheduling is the process of committing resources to tasks and then forming a sequence of events.
Each of these applications has their own issues. Any scheduling problem has elements that are unique. However, most scheduling processes will have common elements:
- A list of jobs or tasks done to a certain standard and due-date.
- Dependencies between these jobs or tasks. E.g. Job B needs to be completed after Job A and before Job C.
- A standard type of resource is required to perform the task. The requirement and capacity is measured in units and time.
- Resources are available during a calendar of working hours. Each unit of resource can only perform one job at once.
- The sequence of jobs is made by working backwards from the last due date, or forwards from the first start date.
Scheduling becomes complex when jobs have many dependencies. If one resource is busy, then the job will wait. The schedule should take this queuing time into account.
You can build tools to automate scheduling . This is made much easier if it is based on structured data. This data needs to be in tables and is better if it comes from a database.
There is a better chance of it being valid and able for a computer to read and process the information.
There are many commercial software applications available for scheduling. Yet, most schedules are made in spreadsheets. The reason is that spreadsheets allow you to work with data and processes together. Spreadsheets are flexible to apply rules to the process of creating the schedule. They are open and transparent; developers and users can see how the rules are applied.
For a tutorial on scheduling in spreadsheets, you can download the following:
Nowadays, the most popular spreadsheet application is Microsoft Excel. However, we have created versions in each, just in case there are any die-hard Lotus or Quattro users out there!
Tutorial for Scheduling in Spreadsheets
|Scheduling_Excel.zip||181kb||.zip file||Download the free tutorial in a .zip format.|
|Scheduling_Excel.xls||505kb||Excel.xls||Download the raw Excel file here.|
|Scheduling_Lotus.zip||181kb||.zip file||Download the free tutorial in a .zip format.|
|Scheduling_Lotus.wk4||710kb||lotus.wk4||Download the raw Lotus file.|
|Scheduling_Quattro.zip||133kb||Quattro.zip||Download the free tutorial in a .zip format.|
|Scheduling_Quattro.wb3||831kb||Quattro.wb3||Download the raw Quattro (.wb3) file.|
The tutorial sets out a series of templates. They are presented so that the logic may be followed by the average, spreadsheet literate person. The templates may also be copied and used to create a live scheduling system. Although the formulas in the templates are applied to only a few records, you simply copy them down to apply them to up to many thousands of rows of data.
THERE ARE NO MACRO’S, AND NOTHING IS HIDDEN
The tutorial takes a step-by-step approach, starting with simple scheduling concepts and techniques, and building slowly to more complex solutions. You will learn how to:
- Understand the essential difference between capacity planning and finite scheduling
- Set up and re-sequence a simple finite schedule
- Display a schedule as a Gantt chart
- Calculate job stop times through a calendar
- Schedule jobs through multiple machines or work centers
- Schedule repetitive production through multiple machines or work centers
- Calculate set-up or change-over times that are dependent on the sequence of jobs
- Evaluate the effect of transfer batch size on lead time
- Set up a pull schedule for just-in-time environments
- Apply a “3 pass” algorithm to optimize due date performance with just-in-time
- Do critical path analysis within a project environment
- Build an integrated master production schedule (MPS) and finite schedule for a make-to-stock environment
- React to non-linear sales forecasts
The tutorial is continually being enhanced – so there is more to come, including:
- 3 pass algorithm for a make-to-stock schedule, to suggest the timing of inventory builds to cope with seasonal demand
- Material requirements planning with dynamic allocation of materials to jobs
If you have a scheduling problem, which is not addressed by the tutorial, don’t hesitate to e-mail us, as we may already have a template that does the job.