Data Systems Theory 101

tags “The very first on-line, real-time, interactive, data base program was double-entry bookkeeping which was created by the merchants of Venice in 1200 A.D.”
– Bryce’s Law

 

Systems work is not as tough as you may feel. Nevertheless, we have a tendency in this organization to complicate factors by altering the vocabulary of systems operate and introducing convoluted ideas and tactics, all of which tends to make it hard to generate systems in a consistent manner. Consequently, there is a tendency to reinvent the wheel with every systems development project. I believe I owe it to my predecessors and the sector all round to describe fundamental systems theory, so that people can discover the frequent ground necessary to communicate and perform. Fortunately, there are only 4 easy, yet crucial, concepts to grasp which I will try to define as succinctly as feasible.
 


1. THERE ARE Three INHERENT PROPERTIES TO ANY Program

Regardless of the sort of program, be it an irrigation program, a communications relay technique, an info method, or what ever, all systems have 3 fundamental properties:

A. A system has a goal – such as to distribute water to plant life, bouncing a communications signal around the country to shoppers, or creating info for individuals to use in conducting enterprise.

B. A system is a grouping of two or a lot more components which are held collectively by way of some widespread and cohesive bond. The bond may possibly be water as in the irrigation program, a microwave signal as utilized in communications, or, as we will see, information in an data program.

C. A method operates routinely and, as such, it is predictable in terms of how it performs and what it will produce.

All systems embrace these straightforward properties. With out any one particular of them, it is, by definition, not a technique.

For our purposes, the remainder of this paper will concentrate on “info systems” as this is what we are usually attempting to make for enterprise. In other words, the development of an orderly arrangement or grouping of elements dedicated to creating information to assistance the actions and choices of a distinct organization. Data Systems are utilised to spend employees, handle finances, manufacture merchandise, monitor and handle production, forecast trends, method customer orders, etc.

If the intent of the system is to produce info, we need to have a excellent understanding of what it is…

 

2. Data = Information + PROCESSING

Information is not synonymous with data. Data is the raw material required to make details. Information by itself is meaningless. It is simply a single element used to identify, describe or quantify an object utilized in a enterprise, such as a item, an order, an employee, a obtain, a shipment, and so forth. A information element can also be generated primarily based on a formula as utilized in a calculation for example:

Net-Spend = Gross-Spend – FICA – Insurance – City-Tax – Union-Dues – (etc.)

Only when information is presented in a distinct arrangement for use by the human getting does it turn out to be information. If the human being cannot act on it or base a selection from it, it is practically nothing a lot more than raw data. This implies information is stored, and data is produced. It is also dependent on the wants and requirements of the human becoming (the consumer of information). Info, therefore, can be defined as “the intelligence or insight gained from the processing and/or evaluation of information.”

The other variable in our formula is “processing” which specifies how data is to be collected, as nicely as its retrieval in order to produce details. This is eventually driven by when the human being wants to make specific actions and choices. Information is not constantly needed “upon request” (aka “on demand”) at times it is necessary once everyday, weekly, month-to-month, quarterly, annually, etc. These timing nuances will eventually dictate how data is collected, stored, and retrieved. To illustrate, assume we collect data once a week. No matter how numerous occasions during the week we make a query of the information base, the information will only be valid as of the final weekly update. In other words, we will see the identical outcomes each day for 1 week. Nonetheless, if we have been to collect the information much more regularly, such as periodically all through the day, our query will produce diverse final results throughout the week.

Our formula of “I = D + P” makes an essential point: if the data is changed, yet the processing remains the exact same, the info will alter. Conversely, if the information remains the same, however the processing adjustments, the details will also change. This leads to a compelling argument to manage data and processing as separate by equal resources which can be manipulated and reused to produce information as necessary.

3. SYSTEMS ARE LOGICAL IN NATURE AND CAN BE PHYSICALLY IMPLEMENTED Numerous Various Methods

An information program is a collection of processes (aka, “sub-systems”) to either collect and store data, to retrieve data and make information, or a mixture of both. The cohesive bond in between these components is the data which need to be shared and reused throughout the program (as properly as other systems). You will observe we have not but discussed the most appropriate way to physically implement the processes, such as by means of the use of manual processes, pc programs, or other workplace technologies. In other words, at this stage, the sub-systems of the method simply define logically WHAT information need to be processed, WHEN it need to be processed, and who will consume the info (aka “finish-customers”), but it most definitely does not specify HOW the sub-method is to be implemented.

Following this, developers decide a appropriate method for physically implementing each sub-system. This choice ought to ultimately be based on practicality and price effectiveness. Sub-systems can be implemented making use of manual procedures, personal computer procedures (application), office automation procedures, or combinations of all 3. Depending on the complexity of the sub-method, many procedures could be involved. Regardless of the procedures chosen, developers have to establish the precedent relationships in the execution of the procedures, either sequentially, iteratively, of decision (thereby enabling divergent paths). By defining the procedures in this manner, from start off to finish, the developers are defining the “function flow” of the sub-system, which specifies HOW the information will be physically processed (including how it is to be designed, updated, or referenced).

Defining details systems logically is beneficial for two causes:

* It offers for the consideration of alternative physical implementations. How one particular developer designs it may extremely effectively be diverse than the next developer. It also provides the indicates to properly establish how a purchased software package might satisfy the requirements. Once more, the choice to select a specific implementation should be based on practicality and cost justification.

* It supplies independence from physical gear, thereby simplifying the migration to a new pc platform. It also opens the door for program portability, for example our consulting firm helped a huge Fortune 500 conglomerate design and style a single logical payroll method which was implemented on at least 3 distinct laptop platforms as utilized by their numerous operating units although they physically worked differently, it was all the identical standard technique generating the same details.

These logical and physical considerations leads to our final concept…

 

four. A Method IS A Solution THAT CAN BE ENGINEERED AND MANUFACTURED LIKE ANY OTHER Solution.

An data program can be depicted as a 4 level hierarchy (aka, “normal method structure”):

LEVEL 1 – Method

LEVEL two – Sub-systems (aka “enterprise processes”) – 2 or more

LEVEL 3 – Procedures (manual, computer, workplace automation) – 1 or much more for each and every sub-program

LEVEL four – Programs (for computer procedures), and Methods (for all others) – 1 or far more for each and every procedure

Click for diagram:
http://www.phmainstreet.com/mba/pride/issss.jpg

Each level represents a different level of abstraction of the method, from basic to specific (aka, “Stepwise Refinement” as identified in blueprinting). This means style is a best-down effort. As designers move down the hierarchy, they finalize style decisions. So a lot so, by the time they finish designing Level 4 for a pc process, they must be ready to write plan supply code primarily based on thorough specifications, thereby taking the guesswork out of programming.

The hierarchical structure of an info technique is essentially no various than any other frequent item to illustrate:

LEVEL 1 – Solution

LEVEL 2 – Assembly – 2 or far more

LEVEL 3 – Sub-assembly – 1 or much more for each assembly

LEVEL 4 – Operation – 1 or more for each and every sub-assembly

Once more, the solution is designed best-down and assembled bottom-up (as identified in assembly lines). This approach is typically referred to as design by “explosion” (top-down), and implementation by “implosion” (bottom-up). An information technique is no various in that it is created best-down, and tested and installed bottom-up. In engineering terms, this notion of a system/solution is generally referred to as a “4 level bill of materials” exactly where the numerous components of the method/item are defined and associated to each and every other in a variety of levels of abstraction (from general to distinct).

This strategy also suggests parallel development. Soon after the program has been developed into sub-systems, separate teams of developers can independently design the sub-systems into procedures, programs, and actions. This is created achievable by the truth that all of the information requirements have been identified as the method was logically subdivided into sub-systems. Data is the cohesive bond that holds the system collectively. From an engineering/manufacturing point of view it is the “parts” utilized in the “product.” As such, management of the information should be relegated to a separate group of people to control in the identical manner as a “materials management” function (inventory) in a manufacturing business. This is typically referred to as “data resource management.”

This process makes it possible for parallel development, which is a more efficient use of human resources on project work as opposed to the bottleneck of a sequential improvement process. Complete sections of the technique (sub-systems) can be tested and delivered ahead of other individuals, and, because information is being managed separately, we have the assurance it will all fit collectively cohesively in the finish.

The normal technique structure is also valuable from a Project Management perspective. Initial, it is utilized to figure out the Operate Breakdown Structure (WBS) for a project full with precedent relationships. The project network is then used to estimate and schedule the project in part and in complete. For instance, each sub-program can be separately priced and scheduled, thereby providing the project sponsors the capability to choose and chose which components of the method they want early in the project.

The common system structure also simplifies implementing modification/improvements to the system. Alternatively of redesigning and reconstructing complete systems, sections of the method hierarchy can be identified and redesigned, thereby saving considerable time and cash.

This analogy among a program and a item is extremely credible and really remarkable. Right here we can take a time-proven notion derived from engineering and manufacturing and apply it to the design and style and development of something a lot significantly less tangible, namely, data systems.

CONCLUSION

Nicely, that’s it, the 4 cardinal concepts of Info Systems theory. I have deliberately attempted to maintain this dissertation concise and to the point. I have also avoided the introduction of any cryptic vocabulary, thereby demonstrating that systems theory can be simply explained and taught so that anyone can understand and implement it.

Systems theory want not be any much more difficult than it truly is.

If you would like to discuss this with me in much more depth, please do not hesitate to send me an e-mail at [email protected]

(For Milt and Les).