Clarify multiple perspectives on what the system is to achieve or change, using input-output transformation diagrams.

To separate out the various subsystems of activity required, we need to define relevant systems, that represent the messiness of the situation, while reducing the context of human activity to a set of ordered transformations that represent multiple perspectives, defined as purposes of the system. A system of human-activity never has a single purpose. It is tempting to think that it has, because this is what we attempt to define when we define computer-system requirements. If we are honest with ourselves, even a computer system has multiple purposes. One of the reasons that requirements analysis is so difficult is because we do not understand this and we do not separate out the different purposes, but get them confused in our heads. By separating out the various purposes of the system, we can model the requisite activities separately, without worrying about tradeoffs and conflicts between sub-systems (that comes later).

There are two types of input-output transformation that can be used. The first, shown as Type A below, is more useful for thinking about what needs to change and why, defining what Churchman calls “inquiring systems.”  It explores the gap analysis between the current state and the future state of the system (from a single perspective of why the system exists). Checkland (2000b) argues that this is the more productive of the two ways to conceptualize a system perspective, as it focuses on gaps in system objectives rather than processing resources.

Type A. Defining Input-Output Transformations As State Changes, to Suggest the Purposes of the System

Personally, I find the type of transformation shown as Type A to be too focused on the rationale for change and not sufficiently focused on how we need to change things. It is very helpful as the basis of thinking through how change is to be accomplished, but less helpful in analyzing what activities are missing, or need to change.

A second type of input-output transformation is used to separate our subsets of the human-activity processes (workflow-steps) that need to be performed for different reasons. This type of transformation, shown as Type B, is better for thinking about the lower-level activities as it focuses attention on the sequence of work-activities that turn the inputs into the outputs specified.

Type B. Defining Input-Output Transformations As Resource Conversions, to Suggest the Purposes of the System

The “system” of purposeful human activity is split up into [related] sub-systems of human-activity that reflect separate purposes (or goals). This is done by defining sets of transformations that explain how the system works (input/output) or how it needs to change. Input-output transformation diagrams separate the various purposes of the system of human-activity. They reflect multiple perspectives, so it is a good idea to include as many people as possible, in providing these perspectives. Include people from all levels of management and work, from all areas of the organization (both involved in, and external to, your human-activity system). Look at the system from as many “angles” as possible and attempt to understand them all – once you have defined them, you should present them to the core stakeholders, so that they may decide which of these perspectives are most useful, in achieving the sorts of changes that they need.

T1Cars parked in dangerous or thoughtless places cause traffic congestionTransformation of inputs to outputsCars parked in safe places ease traffic flows
T2Pedestrians at risk of traffic accidentsTransformation of inputs to outputsPedestrians can move around safely
T3Free for all parkingTransformation of inputs to outputsCharges for time-limited parking
T4No policing of how long people parkTransformation of inputs to outputsPolicing by parking enforcement officers
T5Business/shopping access by car is difficultTransformation of inputs to outputsBusiness/shopping access by car easy & quick
T6People park on sidewalks when no available parking spaces, forcing pedestrians into roadway & endangering disabled peopleTransformation of inputs to outputsIncreased parking availability and enforcement of parking regulations leave sidewalks free for pedestrian use & roadways clear of pedestrians
T7Traffic congestion causes high C02 & particulate emissionsTransformation of inputs to outputsConvenient electric buses & light railways replace need for many car journeys
Table 1. Input-Output Transformations for Root Definitions of Traffic Calming & Management System

A set of input-output transformations is given in Table 1, incorporating both types of transformation (Type A and Type B). Some of these transformations may seem contentious, but try thinking about them from the perspective of the “owner”  of the complete traffic management scheme: State or City Government. I have tried to imagine what their objectives would be and therefore to devise a set of transformations which Government officials would choose to leave in the “system”. These diagrams are most useful if the input relates to the output by a simple transformation – if you cannot put a simple name to the “process” by which the input is transformed to the output, then try another input  or output, or try splitting the input-output diagram into two stages.

Once you have a relatively comprehensive set of transformations that reflect the various purposes of the human-activity system, it is time to define these more fully, as Root Definitions.

Exploring emergent design and the systemic analysis methods needed
for evolving goals & requirements

Copyright © Susan Gasson, 2009-2023.

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Dr. Susan Gasson
College of Computing & Informatics
Drexel University
Philadelphia PA 19104