is difficult to obtain an optimum job mix using manual scheduling techniques, but it can be done. Most often, the  solution  to  obtaining  maximum  throughput  in  a multiprogramming environment (on a continuous 24-hour basis) is to use one of the more sophisticated automated scheduling packages. These packages have all of the considerations we have been discussing programmed into the software. Another  piece  of  job-related  information  to consider is  job  dependencies.  Most  AIS  facilities process  both  single-program  jobs  and  multiprogram systems. Examples of multiprogram systems are the supply and 3-M systems. These systems consist of many programs that are normally executed as separate job steps within a system. Or, the programs may be processed as separate jobs that must be processed in a specific sequence. Therefore, you must know their proper sequence. It would be foolish to execute a job that prints the output of an updated file that had yet to be  updated.  It  should  be  just  as  obvious  if  a  job abnormally terminates that all jobs following it must be canceled and rescheduled, allowing sufficient time for the   terminated   job   to   be   rerun.   Canceling   and rescheduling dependent jobs may seem like an easy task to  perform.  However,  in  reality,  it  can  become  a complex and difficult operation. And  finally,  we  have  priorities  and  deadlines  to consider. Some scheduling methods place primary importance on priority. Each job is assigned a priority, and   the   jobs   are   processed   according   to   the highest-priority  job  that  can  be  scheduled  based  on available resources. Priority scheduling is often used in  automated  scheduling  systems.  Some  scheduling methods  place  primary  importance  on  deadlines, processing jobs according to the earliest deadline or sometimes  latest  deadline.  When  you  prepare  a schedule,  remember  to  take  into  account  job requirements that include the following: l l l * l l l l Data  entry; Job setup and output control functions; Computer processing time; Resource requirements; Operating environment; Job dependencies; Job priorities; and Deadlines. Now  that  we  have  covered  job-related  information, we will discuss AIS facility-related areas and how these can affect your production schedule. You may recall that to prepare an effective sched- ule, you must know your AIS facility’s resources: how work comes into, flows through, and leaves your facil- ity; the capabilities and capacities of your system; and workload demands on the system. As a scheduler, your goal is to match resource capacities (people, places, and things) to workload demands while satisfying user deadlines and priorities. This is often difficult to do, especially when resource capacities vary because of hardware  failures,  specific  shift  requirements, personnel  on  leave,  and  unpredictable  user  demands. Your  workload  can  exceed  capacity,  which  has  a  direct effect on service. Or, the capacity can exceed the workload. This leaves AIS resources underutilized. So how do you reach a happy medium? you might ask. You do it by ensuring that the workload demands put upon the AIS facility’s resources are balanced as much as possible and that the total resources available are kept as close to the maximum capacity as possible. The effective use of resources has a lot to do with how  you  prepare  a  schedule.  However,  other  things affect  scheduling  effectiveness.  One  thing  that  disrupts schedules is the late receipt of input from the users. This often results in a lot of hectic activity. Data entry, possibly I/O control, and computer operations have to try to meet original deadline commitments. If they cannot, you, as the scheduler, have to reschedule jobs, while dissatisfied users complain because their jobs are not out on time. But you say the user has no right to complain? You are right. Often, the users do not realize they are the cause of the delays. So what can you do? Educate them! Inform the users of the effects late input submis- sions have on the schedule. They sometimes do not realize how long it takes to prepare their input. All jobs scheduled should have an established input receipt time. When scheduling, include in your schedule sufficient buffer time between scheduled receipt time and actual due time. And last, but not least, report scheduling deviations and their causes to your superiors. In this way, the process can be reviewed and improved. Something  else  you  have  to  consider  in  connection with  scheduling  effectiveness  is  your  ability  to reschedule  quickly.  You  must  be  prepared  to  make adjustments  to  schedules.  You  will  have  to  contend with power outages, corrective maintenance, deadlines or priority changes, special job requests, and so on. You must  also  consider  processing  delays.  Rejected transactions may have to be reentered before a priority 1-16