POLICY IMPLICATIONS OF SCHEDULING

Data center scheduling requires commitments from user departments or clients in order to observe firm deadlines for submission of input and to allow the DP department enough time to deliver a quality product. If scheduling is to be effective, the organization must have a written policy or management directive listing the relative importance of the applications being processed.

Such a priority list enables the DCOM to develop scheduling policies consis-tent with organizational objectives.

Scheduling in a DP organization usually results from a need for improved efficiency. Data centers sometimes find it difficult to establish or meet user deadlines because of hardware and/or software constraints. In such cases the DCOM should call upon management for policy decisions, particularly when the resolution of scheduling conflicts involves hardware/software acquisition rather than rescheduling. Most scheduling problems can be resolved by ac-quiring additional or larger hardware or by converting to more efficient

sys-DEVELOPING A SCHEDULING SYSTEM 49 terns software. As many DCOMs have learned over the years, however, hardware/software acquisition is not always the answer. In fact, the DCOM who acquires equipment without first determining whether user requirements can be met on existing equipment through improved scheduling is squan-dering financial resources.

Senior management cannot be involved in the resolution of day-to-day computer service problems. The data center ultimately has responsibility for servicing all user departments, and management policy guidelines should give the DCOM responsibility for resolving any scheduling conflicts. These guide-lines should be made available to all users.

User and Data Center Commitment

Today's users are gaining more and more knowledge about the potential uses of computers in their environments. As a result, requests for data center services become more backlogged. By this point, data center clients should understand the relationship of input to output. Users are certainly aware that if the input provided is "garbage," the output will be similarly poor; however, many users do not appreciate the amount of time and effort necessary for the data center to process their jobs correctly. Management, users, and data center personnel must all realize that the data center must have a reasonable period of time to process the work.

Most users do not understand that much more than computer time is necessary to produce quality output. This is an education problem. The pre-processing and postpre-processing steps associated with a given application sys-tem may involve many manual and/or automated procedures requiring hours, while the computer may only require minutes, to process the job. Even the most generous studies have shown that no more than 10 percent of a job's lifetime is spent in the computer.

Users should be educated on the DP state of the art and should understand the points discussed in the following sections.

Batch Applications. These applications usually require little actual com-puter time compared with the time spent in the manual efforts needed to produce the finished product.

Online Data Entry and Edit Applications. Users of these applications should understand that although they are interacting directly with the com-puter system, they are simply generating a clean transaction for later updating through batch programs. Online data collection eliminates such manual steps as data transcription, data keying, data verification, and automated edit runs;

however, users should realize that inquiries will not reflect the most recently input transactions. Users in this environment often fail to understand the batch work required after the terminal network is brought down.

Online Data Base Update Applications. Users of these applications should understand the complexities involved in handling a computer network

50 DATA CENTER OPERATIONS MANAGEMENT

with many online terminals, as well as the potential time delays that result when the system selVices many transactions concurrently.

While eliminating many preprocessing steps, online systems make the scheduling problem more complex, affecting the data center in the following three ways:

• Consuming a significant portion of machine resources during prime-shift hours

• Reducing the time available for batch activity against online files, since most data centers try to avoid processing batch jobs that may degrade terminal response

• Adding a significant batch work load to the data center in the areas of file recovery, backup, and reorganization

Work Flow Analysis

Regardless of the types of systems in a particular environment, every organization has a formal or informal work load structure that encompasses all of the functional areas in the data center. Figure 4-1 illustrates a typical data center work flow structure for a batch-only environment. As pointed out previously, the presence of online systems (unless highly sophisticated) only eliminates the data entry and data control functions. Moreover, online sys-tems complicate the overall scheduling process. The DCOM who understands the work flow in his data center and helps the user understand its complexity will be in a better position to negotiate reasonable user schedules.

The DCOM should prepare a formal presentation to the user community, using graphic materials such as the chart shown in Figure 4-1. Before giving this presentation, the DCOM should collect data on jobs that are pertinent to the users to whom the presentation will be made. If the users understand the time constraints under which the data center functions, it will be easier for the DCOM to obtain user adherence to schedules. On the other hand, the DCOM must understand the requirements for processing a given user's work and be prepared to make similar commitments.

Identifying Critical Areas in the Data Center

In the production-oriented environment found in most medium- to large-scale data centers, the DCOM deals with multiple user deadlines, applica-tions, source-document inputs, application and utility programs, tape files, disk files, card files, output reports, and so on. In addition, the DCOM must be concerned with the quality and quantity of the work performed in the center and the effective utilization of staff, inventory consumables, computer time, and tape and disk libraries. For these reasons, DCOMs in data centers of this type should schedule at least the more critical resources. The most critical resource is usually the computer itself because it has always been the single most costly item in the data center; however, taking into consideration the increases in personnel costs and the decreases in hardware costs in recent years, it is more appropriate to examine the total operation of the data center.

DEVELOPING A SCHEDULING SYSTEM